Internet Protocol
from Nortel Networks
Internet Protocol (IP), the network protocol used by corporations,
governments, and the worldwide Internet, supports many personal,
technical, and business applications, such as electronic funds
transfers, medical records processing, image transfers, and electronic
mail. IP is an important transport service supported by Bay Networks
Switched Internetworking Services (BaySIS™). BaySIS, an open
internetwork architecture based on standards, supports today's
internetworks and their evolution to switched internetworking.
Bay Networks Routing Services (BayRS™) provides all standard
IP functions and supports major Internet Engineering Task Force (IETF)
Request For Comments (RFCs) for protocols including IP, TCP, UDP,
Streams II (ST-II), ICMP, RIP, CIDR, OSPF, BGP-4, Dynamic Host
Configuration Protocol (DHCP), BootP Gateway, Router Discovery, ARP,
RARP, SNMP, Telnet, TFTP, FTP, and IPSO. This support ensures
connectivity and interoperability, allows the internetwork to be
managed effectively, and enhances network security.
Bay Networks enhancements include Equal Cost Multipath, IP
Supernetting, IP Accounting, IP Routing Policies, BGP Pattern Matching
Filters, BGP Communities, Configurable RIP Interface Costs, Unnumbered
Point-to-Point Interfaces, IP RIP v2 Variable Length Subnet Mask
Support, IP RIP v2 Authentication, IP Multicast Routing Support,
Configurable IP Delivery Options, Static Routes, Adjacent Hosts,
Circuitless IP Interface Support, Configurable RIP Timers,
Configurable Broadcast Timers, Configurable Time Out Interval,
Configurable Triggered Updates, Configurable RIP Hold Down Timers,
Router Redundancy, Interface Redundancy, Source Route Bridge
Endstation Support, NetBIOS over IP Support, Ping MIB, Crypto
Resynchronization Support, and Blacker Front-End Support.
Bay Networks IP supports a variety of media, including Ethernet,
Token Ring, FDDI, ATM, and serial interfaces. The router's serial
interfaces operate at rates up to 52 Mbps and support WAN links such
as Frame Relay, SMDS, PPP, ATM DXI, and X.25. Dial Backup,
Dial-on-Demand, and Bandwidth-on-Demand using Analog or ISDN switched
services are also supported. Data Compression, Traffic Prioritization,
Uniform Traffic Filters, IP RIP/OSPF Equal Cost Multipath support, and
Multiline Circuits optimize bandwidth and maximize IP traffic
control. IP is easily configured, monitored, and controlled on all Bay
Networks routers via Bay Networks OptivityŠ family of network
management applications.
IP is a component of BayRS and is supported on all Bay Networks
routers. BayRS supports all major network and bridging protocols,
including OSI, DECnet Phase IV, Novell IPX, Banyan VINES RTP,
AppleTalk Phase 2, XNS, ST-II, APPN, DLSw, NML, Translation Bridge,
Transparent Bridge, and Source Route Bridge.
Benefits
Maximizes Network Performance and Availability
Bay Networks IP implementation maximizes network throughput and
accessibility. OSPF increases network scalability while providing fast
network convergence. Using TCP and BGP-4 provides reliable, loop-free
routing with minimal network overhead. BGP-4 support further reduces
network overhead with support for classless interdomain routing
(CIDR). Network performance is enhanced by Configurable RIP Interface
Costs, which allows user-defined "preferred" route
selection. Additionally, the router's Circuitless IP Interface feature
ensures router reachability if IP interfaces are disabled. By allowing
a WAN circuit to be composed of multiple data paths, Multiline
Circuits increases available bandwidth and provides link
redundancy.
ST-II provides efficient delivery of packet streams requiring
priority transmission and/or guaranteed bandwidth across an
internetwork. Applications ported to ST-II are able to reserve
bandwidth across the network to meet real-time application
demands.
IP Multicast improves bandwidth efficiency by enabling a single
packet to reach multiple stations without flooding all network
segments. Configurable IP Traffic Filter options control IP traffic
flow, increase network security, and ensure proper bandwidth by
prioritizing mission-critical applications.
Maximizes Network Connectivity
Comprehensive network connectivity is ensured by BayRS support of
all major IP protocols, including OSPF, RIP, RIP v2, BGP-4, ST-II,
IGMP, and DVMRP. Additionally, extensive IP address resolution
services are provided through Address Resolution Protocol (ARP),
Reverse ARP (RARP), and BootP Gateway support, while the Adjacent
Hosts feature enhances connectivity by allowing routes to be
predefined for networks and hosts not supporting ARP services.
Furthermore, the router's Source Route Bridge Endstation routes IP
traffic from a source route bridge environment to endstations on
remote LANs over a multiprotocol backbone. IP is supported on the full
range of LAN and WAN interfaces for Bay Networks routers.
Enhances Network Security
Bay Networks routers support the secure transmission of datagrams
using IPSO security labels, as well as Blacker Front-End and KG84A
cryptographic devices. Additionally, the Uniform Traffic Filters,
Static Routes, and IP Routing Policies features control the flow of
data.
Maximizes Network Manageability
By supporting CIDR, Unnumbered Point-to-Point Interfaces, and
Dynamic Host Configuration Protocol (DHCP) together with providing
support for variable length subnet masking with RIP v2 and OSPF, Bay
Networks routers guard against the exhaustion of network address space
and ensure manageability in large networks.
Features
Comprehensive IP Support
Developed by the Department of Defense (DoD), the Internet Protocol
(IP) suite corresponds to the seven-layer OSI reference model. Bay
Networks support of the Internet Protocol suite encompasses all
standard media and protocols as represented in the bottom five layers
of the OSI reference model (see Figure 1). Bay Networks IP
implementation conforms to all standards defined by the Internet
Engineering Task Force (IETF) (see Table 1) and other accepted
standards-setting organizations.
Figure 1 | BayRS IP Protocol Support
The IP suite is supported in BayRS across the entire line of Bay
Networks multiprotocol routers, providing users a variety of choices
to meet a broad range of networking demands.
Internet Protocol (IP) IP is a connectionless datagram
delivery protocol that performs addressing, routing, and control
functions for transmitting and receiving datagrams over a network. As
a connectionless protocol, IP does not require a predefined path
associated with a logical network connection. As packets are received
by the router, IP addressing information is used to determine the best
"next hop" a packet should take enroute to its final destination. As a
result, while IP does not control data path usage, if a resource
becomes unavailable, IP is able to immediately route datagrams around
the affected area.
IP datagrams begin with a packet header. The header identifies the
version of IP protocol used to create the datagram, the header length,
the type of service required for the datagram, the length of the
datagram, the datagram's identification number, fragmentation control
information, the maximum number of hops the datagram can be
transported over the internetwork, the protocol format of the data
field, the source and destination addresses, and potentially IP
options (see Figure 2).
Figure 2 | IP Datagram Format
Internet Streams Protocol II (ST-II) Bay Networks routers
support the ST-II resource reservation protocol. ST-II provides
efficient delivery of packet streams requiring priority transmission
and/or guaranteed bandwidth across an internetwork. Additional
features of the ST-II control protocol include bandwidth reservation
and quality of service guarantees. ST-II is suitable for
videoconferencing, real-time simulation, and other multimedia
applications. ST-II can coexist in a network also using IP,
DVMRP/MROUTED, BGP, OSPF, RIP, and static routing.
Transmission Control Protocol (TCP) TCP provides a
reliable, connection-oriented, transport layer service for IP. Using a
handshaking scheme, TCP provides the mechanism for establishing,
maintaining, and terminating logical connections between
hosts. Additionally, TCP provides protocol ports to distinguish
multiple programs executing on a single device by including the
destination and source port number with each message. TCP provides
reliable transmission of byte streams, data flow definitions, data
acknowledgments, data retransmissions, and multiplexing multiple
connections through a single network connection.
Bay Networks IP implementation supports extension to TCP, per RFC
1323 (Van Jacobson TCP), including Windows Scale, a fast
retransmit/fast recovery algorithm, and round-trip time
measurement. These extensions improve performance and provide reliable
operations over high-speed paths.
User Datagram Protocol (UDP) UDP provides an unreliable,
connectionless datagram transport service for IP. This protocol is
used for transaction-oriented utilities such as the IP standard Simple
Network Management Protocol (SNMP) and Trivial File Transfer Protocol
(TFTP). Like TCP, UDP works with IP to transport messages to a
destination and provides protocol ports to distinguish between
software applications executing on a single host. Unlike TCP, however,
UDP avoids the overhead of reliable data transfer mechanism by not
protecting against datagram loss or duplication.
Routing Information Protocol (RIP) RIP is a
distance-vector, interior gateway protocol (IGP) used by routers to
exchange routing information (see Figure 3). Through RIP, endstations
and routers are provided with the information required to dynamically
choose the best paths to different networks. RIP uses the total number
of hops between a source and destination network as the cost variable
in making best path routing decisions. The network path providing the
fewest number of hops between the source and destination network is
considered the path with the lowest overall cost.
The maximum allowable number of hops a packet can traverse in an IP
network implementing RIP is 15 hops. By specifying a maximum number
of hops, RIP avoids routing loops. A datagram is routed through the
internetwork via an algorithm that uses a routing table in each
router. A router's routing table contains information on all known
networks in the autonomous system, the total number of hops (hop
count) to a destination network, and the address of the "next hop"
router in the direction of the destination network.
In a RIP network, each router broadcasts its entire RIP table to
its neighboring router every 30 seconds. When a router receives a
neighbor's RIP table, it uses the information provided to update its
own routing table and then sends the updated table to its
neighbors.
This procedure is repeated until all router's have a consistent
view of the network topology. Once this occurs, the network has
achieved convergence.
Figure 3 | Routing Protocol Usage
Open Shortest Path First Version 2 (OSPF-2) OSPF is a
second-generation standards-based IGP that enables routers in an
autonomous system to exchange routing information. An autonomous
system consists of a group of routers under the administrative control
of one authority. OSPF minimizes network convergence times across
large IP internetworks.
Routers supporting OSPF exchange routing information within an
autonomous system using a link-state algorithm. After initial network
convergence, protocols based on link-state algorithms issue routing
update messages only when a change in topology occurs. When a topology
change occurs, the affected router immediately notifies its
neighboring router about the topology change only, instead of the
entire routing table. The neighbors, in turn, pass the updated
information to their neighboring routers, reducing the amount of
traffic on the internetwork. Since topology change information is
propagated immediately, network convergence is achieved more quickly
than relying on the timer-based mechanism used with RIP.
With OSPF, autonomous systems can be segmented into areas -- a
group of contiguous networks, hosts, endstations, and routers. The use
of areas reduces internetwork overhead by decreasing the amount of
topology change information trans-mitted within the autonomous
system. OSPF also provides the ability to configure cost metrics for
each router interface, allowing preferred paths to be specified for
enhanced traffic control. If the preferred path fails, OSPF will
automatically compute a new path. Additionally, OSPF's variable length
subnet mask feature in-creases network efficiency by allowing the
network to be divided into subnets of varying sizes and communicate
route mask information to adjacent routers. The reachability of
multiple networks within an area is summarized through OSPF's route
summarization feature. Summary advertisements communicate between
areas, enabling several networks to be compressed into one
advertisement. This reduces link advertisements overhead by allowing
one link advertisement to be generated for all subnets in an area.
OSPF is increasingly being adopted within existing autonomous
systems that previously relied on RIP's routing services. OSPF routers
simultaneously support RIP for router-to-endstation communications,
and OSPF for router-to-router communications. Bay Networks IP
implementation supports OSPF/RIP coexistence, which allows OSPF and
RIP to share routing information (see Figure 4). This ensures
communications within an internetwork and provides a smooth migration
path for introducing OSPF into existing networks.
Figure 4 | OSPF/RIP Coexistence
Classless Interdomain Routing (CIDR) CIDR defines a
strategy for IP address assignment. It replaces address classes with
address prefixes. This strategy conserves address space and slows the
explosive growth of routing tables.
An example of a CIDR aggregated address, referred to as a supernet
address, is 192.32.0.0/16, where 192.32.0.0 represents the address
prefix, and 16 is the prefix length in bits. Such an address
represents destinations from 192.32.0.0 to 192.32.255.255. CIDR is
supported by OSPF and BGP-4.
Border Gateway Protocol Version 4 (BGP-4) BGP-4 is an
exterior gateway protocol that enables routers in different autonomous
systems to exchange routing information (see Figure 3). It also
provides a set of mechanisms for facilitating CIDR by providing the
capability of advertising an arbitrary length IP prefix and thus
eliminating the concept of network "class" within BGP. BGP uses TCP to
ensure delivery of interautonomous system information. Update messages
are generated only if a topology change occurs and contain information
only about the change. This reduces network traffic and bandwidth
consumption used in maintaining consistent routing tables between
routers.
Additionally, the routers support BGP-OSPF interaction, which
permits importing BGP routes into OSPF. Support of BGP and BGP-OSPF
interaction ensures communications between a wide variety of
dissimilar autonomous systems.
Also, BGP-4 provides the ability to configure the routing policies
required by the Internet providers (for example, route aggregation,
including aggregation of AS paths). This enhances route selection
control. BGP-4 can coexist with RIP, RIP v2, EGP, OSPF, and static
routing.
Bay Networks routers support BGP-3 as well as BGP-4. However, with
the advent of BGP-4, BGP-3 has been moved to historical status and
therefore should only be used if absolutely necessary.
Exterior Gateway Protocol Version 2 (EGP-2) EGP-2 is the
exterior gateway protocol that features a neighbor acquisition
mechanism that allows two routers to agree to support a mutual
connection and exchange routing information. The EGP routing table
contains a list of routers, the networks those routers can reach, and
their associated cost metric. To maintain network reachability
information using EGP, a router transmits its entire routing table in
response to a poll command. Bay Networks routers support polling
intervals from 120 to 480 seconds. Like BGP-3, EGP-2 has been moved to
historical status; therefore, Bay Networks recommends the use of
BGP-4.
Router Discovery Router Discovery enables hosts attached
to multicast or broadcast networks to discover the IP addresses of
their neighboring routers. An extension of the Internet Control
Message Protocol (ICMP), Router Discovery eliminates the need for
manual configuration of router addresses and is independent of any
specific routing protocol.
Using Router Discovery, each router periodically multicasts
discovery messages, referred to as Router Advertisements, announcing
the IP address(es) of that interface. Hosts discover the addresses of
their neighboring routers simply by listening for advertisements.
When a host attached to a multiaccess link initializes, it can
multicast or broadcast a Router Solicitation to ask for immediate
advertisements rather than waiting for the next periodic ones to
arrive. If no advertisements are forthcoming, the host may retransmit
the solicitation. Any routers that subsequently initialize, or that
were not discovered because of packet loss or temporary link
partitioning, are eventually discovered by reception of their periodic
(unsolicited) advertisements.
The router discovery messages enable hosts to discover the
existence of neighboring routers, but not which router is best to
reach a particular destination. If a router knows of a better route to
a particular destination, it issues an ICMP Redirect to the hosts. The
Host Table will then consist of a default and ICMP-learned host
routes.
Router advertisements include a user-configurable advertising rate
and an age field. The advertising rate specifies the frequency with
which a router advertises its address. The age field specifies the
maximum length of time that the advertised addresses are to be
considered as valid router addresses by hosts, in the absence of
further advertisements. This is used to ensure that hosts eventually
forget about routers that fail or become unreachable.
Address Resolution Protocol (ARP) and Proxy ARP ARP enables
an IP host to determine the MAC-layer address of a target host when
only the target host's IP address is known.
To transmit a datagram, an IP device must know the IP destination
address represented in the datagram's IP header. A router makes packet
forwarding decisions based on the IP destination address. Once a
routing decision has been determined, the router forwards the packet
to the next hop network, providing the best path to the packets
ultimate destination. To accomplish this, the MAC-layer address of
the next hop interface is added to the datagram and the packet is
forwarded out the appropriate router interface.
If the next hop MAC-layer address is not known, the router first
broadcasts an ARP Request packet to determine the MAC-Address of the
next hop interface. When the destination with the matching IP address
receives the broadcast, it responds with its MAC-layer address, which
is entered in the originating router's cache for future use.
Per RFC 826, a router and host must be attached to the same network
segment to accomplish ARP. ARP Request broadcasts cannot be forwarded
by another router to a different network segment. If a host requests
the hardware address of a host on another network, Proxy ARP must be
used. Proxy ARP support allows an intermediate router to answer the
request for the remote destination host.
Reverse Address Resolution Protocol Server (RARP Server) A
RARP server allows hosts to obtain IP addresses from the router. Hosts
added to the network broadcast a RARP Request, specifying itself as
the source and supplying its MAC-layer address in the frame's
Destination Hardware Address field. When the RARP server receives the
RARP request, it enters an IP address in the RARP request's
Destination IP address field, changes the message type to a Reply, and
sends the packet back to the host that transmitted the request, using
the host's MAC-layer address.
Simple Network Management Protocol (SNMP) SNMP is the
standard protocol used to monitor and control IP routers and attached
networks. This transaction-oriented protocol specifies the transfer of
structured management information between SNMP managers and agents. An
SNMP manager, residing on a workstation, issues queries to gather
information about the status, configuration, and performance of the
router. An SNMP agent, operating in each Bay Networks router, responds
to the queries issued by the manager and generates activity
reports. In addition to responding to SNMP queries, the router's SNMP
agent software transmits unsolicited reports, referred to as traps, to
the SNMP manager when events, such as the number of network
collisions, exceed user-configured thresholds.
Each router maintains a set of configuration and performance
variables in a database, referred to as a Management Information Base
(MIB). All Bay Networks routers contain a MIB II-compliant SNMP agent
that responds to SNMP SET/GET requests for configuration, monitoring,
and control of network interfaces. Site Manager and
ControlCenter™, Bay Networks node management applications for Bay
Networks routers, use SNMP for router configuration, monitoring, and
control. The routers can also be managed from popular general-purpose
SNMP management systems such as Hewlett-Packard's OpenView, Sun
Microsystem's Solstice Domain Manager, and Tivoli NetView for AIX.
Virtual Terminal Protocol (Telnet) Bay Networks enhances
router installation and maintenance by supporting Telnet, the simple
remote terminal protocol. Through incoming Telnet sessions, a Bay
Networks router's Command Console interface or the Technician
Interface can be accessed by a local or remote terminal. Outbound
Telnet support enables Technician Interface to also originate an
outgoing Telnet session to another Bay Networks router or to other
network equipment that accepts inbound Telnet. This provides access to
remote routers in nonroutine situations when ControlCenter, Site
Manager, or SNMP is unavailable.
The Technician Interface is based on a simple command line
interpreter and provides SNMP-based access to the MIB, displays the
router's event log, and supports file system management and other
administrative commands.
Trivial File Transfer Protocol (TFTP) A Bay Networks
router's support of TFTP allows a network management station to
download configuration information to a router or group of routers and
retrieve information from a router via Site Manager or
ControlCenter. Bay Networks routers include client and server
implementations of TFTP, enabling efficient transmission and receipt
of files across the internetwork. TFTP provides file transfer
capabil-ities with minimal network overhead. Although TFTP uses UDP to
transport files between network devices, it supports timeout and
retransmission techniques to ensure data delivery.
File Transfer Protocol (FTP) The Bay Networks router's
support of FTP enables a network management station to initiate
router-to-host, host-to-router, and router-to-router data transfers
over TCP via Site Manager or ControlCenter. This implementation
supports RFC 959 (File Transfer Protocol) to ensure that data is
transferred reliably and efficiently. FTP is supported on all Bay
Networks routers and by all the router's LAN, serial, and ATM
interfaces.
Internet Protocol Security Option (IPSO) The IP
implementation supports the Department of Defense (DoD) IPSO on a
per-interface basis, ensuring that the integrity of datagrams
requiring a high level of security is not compromised when received or
transmitted by a Bay Networks router. IPSO enables hosts to add
security labels to IP datagrams for classification purposes. Through
IPSO, a host can label individual IP datagrams with one of four
security classifications -- Top Secret, Secret, Confidential, and
Unclassified -- and a set of protection authorities. These security
labels can be compared on received, originated, or forwarded IP
datagrams.
Dynamic Host Configuration Protocol (DHCP) Bay Networks
routers support extensions to Bootstrap Protocol (BootP) to enable
full support of the Dynamic Host Configuration Protocol (DHCP), used
between endstations to enable dynamic assignment of IP addresses.
In addition to supporting DHCP datagram transmission, Bay Networks
routers provide features to further enhance DHCP operations. The DHCP
Preferred Server Table provides direct control over which DHCP servers
should participate in client to server DHCP interactions. This feature
reduces bandwidth consumption by converting DHCP broadcast traffic
into DHCP Directed Broadcasts (unicast).
DHCP relies on BootP as its transport mechanism. BootP Relay
ensures client and server DHCP transactions are properly transported
across IP subnets and WAN links. DHCP Filters allows Bay Networks
router interfaces to be configured as either accepting or rejecting
DHCP traffic on a segment while continuing to relay BootP
traffic. Conversely, interfaces connected to DHCP servers that do not
require other types of BootP traffic to traverse the segment are now
able to filter all BootP traffic except those BootP packets carrying
DHCP information. This feature increases network security, bandwidth
availability, and provides direct control over which DHCP servers
allocate IP addresses to different subnets across the network.
BootP Gateway (BootP Relay) Bay Networks routers support
RFC 951, Section 8, of the Bootstrap Protocol (BootP) specification
and RFC 1542, Clarification's and Extension to BootP for DHCP.
With BootP Gateway, a Bay Networks router can transfer BootP
packets, enabling diskless clients to boot from a server located on a
network several hops away. BootP Gateway support can be enabled by
configuring BootP Relay on individual network interfaces to receive
and forward both BOOTREQUEST and BOOTREPLY packets to their
destinations.
Bay Networks support for RFC 1542 also ensures full routing support
for IP networks using the Dynamic Host Configuration Protocol for
dynamic IP host address assignment and maintenance.
Bay Networks IP Enhancements
Bay Networks supports many advanced features as part of its IP
implementation. These include Equal Cost Multipath, IP Supernetting,
IP Accounting, IP Routing Policies, BGP Pattern Matching Filters, BGP
Communities, Configurable RIP Interface Costs, Unnumbered
Point-to-Point Interfaces, IP RIP v2 Subnet Masks, IP RIP v2
Authentication, IP Multicast Routing Support, Configurable IP Delivery
Options, Static Routes, Adjacent Hosts, Circuitless IP Interface
Support, Configurable RIP Timers, Router Redundancy, Interface
Redundancy, Source Route Bridge Endstation Support, NetBIOS over IP
Support, Ping MIB, Crypto Resynchronization Support, and Blacker
Front-End Support. These enhancements optimize internetwork
reliability, availability, performance, and security.
Equal Cost Multipath Bay Networks IP implementation
supports IP/RIP and OSPF Equal Cost Multipath forwarding
algorithms. This allows sites to take advantage of the aggregate
bandwidth available on the network by splitting multipacket
transmissions with the same destination over multiple paths in the
network. In addition to stripping over equal cost interfaces,
multipath provides an address-based forwarding technique that captures
source and destination addresses and forwards them along with other
packets with the matching addresses over the same interface. This
technique eliminates the occurrence of out-of-order packet delivery
and ensures that connectivity is maintained between clients and
servers.
IP Supernetting IP Supernetting enables Bay Networks
routers to support a nonstandard IP subnetmask. This allows a large
number of IP devices in an IP subnet to share a single IP
gateway. Supernetting enhances route aggregation by allowing a group
of IP subnets to be advertised as a single supernet, reducing the
number of routing table entries.
IP Accounting Bay Networks routers provide a number of IP
accounting capabilities that enhance the ability to bill for network
usage based on which network resources have been accessed and/or how
much data passed between locations. Via Bay Networks IP accounting
capabilities, billing statistics can be collected based on source and
destination addresses on outbound Frame Relay interfaces. Data
collected reduces the total packets and bytes transmitted on the Frame
Relay interfaces for each source and destination address
pair. Additionally, a Maximum active database size and a Trap level
size threshold parameter is provided to ensure that accounting data
collected by the billing application and data collection is maintained
when the database is near maximum capacity.
IP Routing Policies IP Routing Policies are the rules that
allow for the definition of criteria for routes accepted into domain
and for routes advertised to other domains. The IP Policies govern the
addition of routing information to the routing tables and propagation
of routing information. The Policy Filter features "filterable" fields
that are consistent among the different protocol, and the syntax can
represent single network entries and/or ranges of networks. Policy
Filters provide the ability to aggregate and deaggregate
routes. Within Policy Filters, Import Route Filters are referred to as
Accept Policies, and Export Route Filters as Announce Policies.
Announce Policy rules contain the network advertisement list. This
list controls the actual network advertisements that the router
delivers to its neighbors. For BGP-4 and OSPF, it provides the
ability to aggregate subnets and networks into supernets.
BGP Pattern Matching Filters The AS_PATH attribute can be
used by policies to control the distribution of routing information by
Bay Networks routers. Bay Networks BGP AS_PATH Pattern matching filter
feature allows the construction of regular expression based rules that
can be applied to the AS_PATH attribute to increase BGP network
control by limiting the transmission of advertisements of network
resources.
BGP Communities Bay Networks support of the BGP
Communities attribute simplifies the configuration of a router in a
BGP environment by simplifying the policies that control distribution
of routing information. This reduces the complexity of maintaining a
BGP network. BGP routers that share common properties can be grouped
into clusters (communities). Routing policies can then be applied
based on these clusters instead of applying routing policies on a
per-router basis. These policies can control which routing
information to accept, prefer, or distribute to other neighbors. A
router can be configured to be a member of multiple clusters, as long
as the router shares a common property within each cluster.
Configurable RIP Interface Costs The IP implementation
supports configurable RIP costs on a per-interface basis. This feature
is especially useful in topologies having two or more paths, of
different bandwidths, connecting two networks. A path's cost is
assigned during initial configuration, and can be changed anytime to
meet new requirements.For example, in Figure 5, traffic generated by endsystem ES 1 on
Network A can be directed to the server on Network B over the two T1
circuits rather than the single 56-Kbps circuit with only "two hops."
This can be accomplished by assigning a RIP interface cost of 3 to
interface 2 of router R1, and assigning a RIP interface cost of 1 to
interfaces 1 and 3 of routers R1 and R2, respectively. Because the
total cost to reach router R3 via the T1 links is 2, compared to a
cost of 3 for the 56-Kbps link, the primary path consists of T1
links. If the T1 network should fail, the lower bandwidth 56-Kbps link
is automatically used as a backup. The ability to assign different
cost values to each interface optimizes bandwidth use.
Figure 5 | Configurable RIP Interface Costs
Unnumbered Point-to-Point Interfaces Bay Networks IP
implementation conserves IP address space by enabling configuration of
an IP Point-to-Point interface without assigning a corresponding IP
network number. Bay Networks Unnumbered Point-to-Point Interfaces
distinguishes each interface with a unique identifier, such as a
Router ID, enabling multiple unnumbered interfaces to be flagged with
a unique circuit number. Protocol support is provided for RIP, RIP v2,
OSPF, BGP-4, and DVMRP.
IP RIP v2 Variable Length Subnet Mask Support RIP v2
variable length subnet mask support augments Bay Networks existing IP
implementation, providing the information and tools needed to
effectively build and maintain large enterprise networks.
IP RIP v2 Authentication Support By supporting RIP v2
Authentication, Bay Networks routers enhance network seccurity by
preventing the insertion of fraudulent routing information into the
routers. With RIP v2 Authentication only routers with valid passwords
can insert routing information into the router's table.
Authentication is a per message function that uses a type 2 simple
password. Routers configured to authenticate RIP v2 messages accept
RIP v1 messages and RIP v2 messages that pass authentication testing.
All unauthenticated and failed authentication RIP v2 messages are
discarded. For maximum security, RIP-1 messages should be ignored when
authentication is in use.
IP Multicast Routing Support By supporting IP
Multicasting, a Bay Networks router allows messages to be sent to
members of a multicast group simultaneously. Data packets are sent
only to the endstations who have joined and are specified as members
of that multicast group. This improves bandwidth efficiency by
reducing network traffic.
IP multicast routing is supported via the Distance Vector Multicast
Routing Protocol (DVMRP) and the Internet Group Management Protocol
(IGMP). Based on distance vector or Bellman-Ford technology, DVMRP
routes multicast a datagram within a single autonomous system. Further
optimization of multicast routing is provided by DVMRP pruning, a
means of forwarding IP multicast datagrams to only those network
segments on which members of that multicast group reside. DVMRP
pruning reduces unnecessary network traffic and improves performance
of multicast applications, such as videoconferencing and trading floor
distribution. DVMRP also specifies the tunneling of IP multicasts
through non-multicast routing-capable IP domains. DVMRP can coexist
with BGP, OSPF, RIP, RIP v2, and Static Routes.
DVMRP Traceroute is also supported by Bay Networks IP
implementation. This feature provides the ability to diagnose and
isolate a network's problems by tracing the path a multicast packet
traverses from a receiver to a particular source. The trace-route
facility implemented in Bay Networks routers and accessed by external
diagnostic programs supports the ability to trace the path that a
packet would take from some destination to some source, the ability to
isolate packet loss problems (e.g., congestion), the ability to
isolate configuration problems (e.g., TTL threshold), and the ability
to minimize the number of packets sent (e.g., no flooding, no
implosion).
IP multicasting uses the IGMP as the protocol to communicate
between hosts and multicast routers on a single physical network to
establish a host's membership in particular multicast groups. IGMP
also allows endstations to join and leave multicast groups.
Configurable IP Delivery Options Bay Networks routers
provide the ability to configure three IP Traffic Filter delivery
options: Forward to Next Hop Interface, Forward to First Up Next Hop
Interface, and Forward to IP Address. This capability provides control
of IP traffic flow throughout the network, increases network security,
and ensures allocating proper bandwidth and forwarding priority to
mission-critical applications.
Using Forward to Next Hop Interface or Forward to First Up Next Hop
Interface, filtered IP packets can be sent to up to 40 network
interface addresses. Whereas Forward to Next Hop forwards packets to
multiple addresses meeting the defined filtering criteria, Forward to
First Up Next Hop will forward packets to only the first network
address reachable at the time of transmission. This allows IP packets
to be forwarded to a next hop interface while at the same time
ensuring the reliability of the transmission through verification of
the network being reachable before the packet is sent out an
interface. Additionally, network resilience is enhanced by ensuring
packets are not forwarded to network locations no longer
reachable.
The Forward to IP Address traffic filter delivery option can be
used when forwarding specific traffic to a specific network
location.
Static Routes An administratively configured IP route can
be manually entered into an IP routing table through the Static
Routing feature. Available bandwidth is increased by eliminating the
need to periodically transmit dynamic routing updates over the
network. Additionally, because static routes do not "age-out" of IP
routing tables, remote offices or mobile workgroups using a dial-up
service, such as Dial-on-Demand to communicate with a central site,
are ensured that a data path exists.
Adjacent Host Support Adjacent Host Support allows a
transmission path to be specified from a router to a host that resides
on a locally attached network segment. This feature is typically
configured for hosts that do not implement ARP and predefines the
IP/data link address pair for each such local host. By supporting
topologies that include non-ARP devices, the Adjacent Host feature
enhances connectivity.
Adjacent hosts can also be configured for a local host that does
support ARP to preempt the ARP process. By preresolving the host's
IP/data link address pair, Adjacent Host configurations reduce network
overhead by avoiding ARP handshaking.
Circuitless IP Interface The Circuitless IP Interface
feature allows a backup IP address to be specified for a router
without mapping it to a specific circuit. This ensures that the router
is reachable if one or more of the router's IP interfaces becomes
disabled. A malfunctioning router can still receive routing update
messages and communicate with network management systems using its
circuitless IP address, reducing the impact of hardware
malfunction. IP traffic is received from and transmitted to the
circuitless interface using the same method as any other IP
interface.
Configurable RIP Timers Configurable RIP timers encompass
four value-added features: Configurable Broadcast Timers, Configurable
Time Out Intervals, Configurable Triggered Updates, and Configurable
RIP Hold Down Timers. These provide direct control over the amount of
traffic generated on network links and are particularly beneficial in
dial-on-demand environments because they reduce bandwidth consumption
and eliminate the risk of dial connections being established due to
propagation of RIP maintenance traffic.
- Configurable Broadcast Timers control the frequency in
which a Bay Networks router propagates periodic IP RIP routing table
broadcasts. RIP broadcast intervals are now configurable from as low
as once every 5 seconds to as high as once every 24 hours.
- Configurable Time Out Intervals are used for entries
within an IP RIP routing table. Standard IP RIP age-out intervals will
age out a route entry within the IP RIP routing table if an update for
that route has not been received for 90 seconds (three times the
standard broadcast interval). Configurable Time Out Intervals provide
users direct control over how long RIP entries are maintained before
being deleted if no updates are received.
- Configurable Triggered Updates allow a Bay Networks
router to be configured to immediately propagate network change
information when learned. Enabling Triggered updates results in the
router sending out network change information as soon as it is
learned, while disabling triggered updates configures the router to
send network change information only when a periodic RIP broadcasts is
propagated.
- Configurable RIP Hold Down Timers enable the time
period a router will wait before propagating network topology change
information. This allows the router to group multiple changes into a
single topology change update.
Router Redundancy Bay Networks routers support redundant
router capability that provides protection against catastrophic events
such as fire or flood, which can eliminate any single router. In
Router Redundancy, two identical routers are used. One of the routers
is placed in Primary mode and the other in Backup mode. If the
Primary router fails, the backup will become active and resume routing
traffic. In addition to IP, IPX and Source Route Bridge are supported
by this feature.
Interface Redundancy Bay Networks Ethernet, Token Ring,
FDDI, and ATM interfaces can be configured for 1-for-1 redundancy,
allowing two similar media LAN interfaces on the same or different
network interface module in the same router to be attached to a single
LAN. One of the interfaces is designated primary and is fully
operational while the other is in a nonoperational backup mode. If the
primary interface fails, the backup interface becomes operational,
ensuring continued availability. In addition to IP, IPX and Source
Route Bridge are supported by this feature.
Source Route Bridge Endstation The Source Route Bridge
Endstation feature enables routable traffic generated in a source
route bridge environment to be routed to endstations on remote LANs
over a multiprotocol backbone. This reduces source route bridge
overhead on a wide area network and maximizes network availability by
rapidly rerouting around a failed link.
When Source Route Bridge Endstation is enabled, a Bay Networks
router attached to a Token Ring in a source route bridge environment
functions as an endstation and router. All traffic is source route
bridged within the local Token Ring environment. IP traffic intended
for a destination on a LAN interconnected via a multiprotocol backbone
is routed over the backbone by the Bay Networks node.
NetBIOS over IP Support Bay Networks routers can route
NetBIOS frames encapsulated within IP datagrams to provide efficient
routing of NetBIOS information across an IP-based internetwork. The
router's NetBIOS over IP support is based on RFC 1001 and RFC 1002
broadcast node (b node). This allows the router to rebroadcast NetBIOS
packets beyond a local subnet to ensure unique NetBIOS name
registration and provide immediate visibility of new NetBIOS resources
as they become available on the network.
The router also provides a number of enhancements that improve the
efficiency of routing NetBIOS over IP -- NetBIOS Name Caching, NetBIOS
Broadcast Filters, and NetBIOS Local Acknowledgment. These features
improve network performance, enhance traffic control, and increase
bandwidth availability.
Ping MIB The Bay Networks router's Ping MIB tracks network
availability and response. The Ping MIB provides diagnostic
capabilities to enhance network management by enabling manual
verification of connectivity across the network. Matrices such as
those for source and destination IP addresses can be easily created
using Site Manager or ControlCenter, Bay Networks node management
applications for Bay Networks routers. Additionally, multiple
destination addresses are supported for each source address.
Crypto Resynchronization A Bay Networks router can
automatically detect the loss of synchronization between KG84A
cryptographic encryption devices and initiate resynchronization. KG84A
devices communicate over a point-to-point serial line and connect to a
Bay Networks router via a V.35 Synchronous interface.
Blacker Front-End (BFE) Bay Networks routers can be
connected directly to Blacker Front-End encryption devices to protect
sensitive data transmitted over an unsecured X.25 network. The Blacker
Front-End Device provides the router with encryption services and
access to the X.25 network. The Bay Networks router communicates with
the Blacker Front-End Device over an X.25 Synchronous interface, which
supports data rates between 1,200 bps to 64 Kbps and complies with the
1983 DDN X.25 Host Interface Specification.
Local Area Network Support
All Ethernet, Token Ring, and FDDI network interfaces for Bay
Networks routers support IP. The routers support SNAP and Ethernet
encapsulation over Ethernet/802.3, SNAP encapsulation over FDDI, and
LLC over Token Ring/802.5 media.
Wide Area Network Support
All serial interfaces for Bay Networks routers support IP. Serial
interfaces operate at rates ranging from 1,200 bps to 52 Mbps, full
duplex, and support V.35, RS-232, RS-449/RS-422 balanced, X.21,
MCT1/E1, ISDN BRI, ISDN PRI, and HSSI. The Synchronous interfaces
support either internal or external clocking. Networks can also be
interconnected via a variety of WAN services, including X.25, Frame
Relay, SMDS, ATM DXI, ISDN, or point-to-point circuits using PPP or
HDLC encapsulation.
Dial Backup, Dial-on-Demand, and Bandwidth-on-Demand are also
supported by the IP implementation over V.35 and RS-232
interfaces.
ATM Network Support
Bay Networks router ATM link module interfaces and ATM Data
Exchange Interface (DXI) software support Bay Networks IP
implementation. ARE link modules operate at up to 155 Mbps and support
SONET/SDH single and multimode fiber, DS3/E3 single-mode fiber, and
TAXI multimode fiber.
The ATM DXI operates over HSSI, V.35, and RS-449 interfaces at up
to 52 Mbps and can be used in all Bay Networks routers. This software
interface fully complies with Modes 1a, 1b, and 2 of the ATM Forum's
DXI specification for communications between routers and DSU/CSUs.
Traffic Management
Bay Networks provides comprehensive traffic management capabilities
through Data Compression, Traffic Prioritization, Uniform Traffic
Filters, IP RIP/OSPF Multipath, and Multiline Circuit Support.
Data Compression Based on a Lempel-Ziv algorithm, Bay
Networks software- and hardware-based Data Compression features
maximize internetwork performance by reducing the amount of bandwidth
required to transport data over the wide area. Configurable on a
per-circuit or link basis, Data Compression provides features that
enhance performance, reduce WAN costs, and maximize efficiency of
available network segments. For example, Data Compression over Frame
Relay allows sites to subscribe to lower committed information rates
(CIR) while transmitting compressed throughput at a greater rate than
the original line rate. The BayRS software-based compression offering
is fully interoperable with the hardware-based data compression
coprocessors for the Backbone Node (BNŠ), Access Stack Node
(ASN™), and System 5000™ Router Module platforms, providing
an end-to-end compression solution.
Bay Networks software-based Data Compression feature is supported
by all BayRS routers and is supported over Dial-up lines, including
ISDN and leased lines using PPP, Frame Relay, and X.25. Bay Networks
software-based payload compression provides a compressed throughput of
up to 1.2 Mbps, full duplex, over a 512-Kbps link.
Designed for maximum compression and throughput over costly wide
area network facilities, the hardware-based data compression
coprocessors off-load the compression/decompression tasks from the
processor module, allowing it to focus on functions such as forwarding
and filtering packets, responding to SNMP requests, and calculating
routing table updates. Hardware-based coprocessors for the BN, ASN,
and System 5000 Router Module platforms are ideal for environments
requiring compression over multiple WAN connections aggregated at the
central site router.
Hardware-based Data Compression delivers an aggregate compressed
throughput of up to 16 Mbps. For example, one can effectively
transmit up to 4 Mbps worth of compressed data for up to two
full-duplex E1 lines. Hardware coprocessor modules are available as a
daughtercard for the Octal Sync Link Module on the BN, and as a net
module for the ASN and System 5000 Router Module. The coprocessor Net
Module provides compression over a variety of net modules, including
the Dual Synchronous, ISDN BRI/Dual Synchronous, Quad ISDN BRI,
MCE1/PRI, and Dual MCT1/PRI.
These hardware coprocessors support PPP and Frame Relay and are
configurable on a per-circuit or per link basis. The hardware
coprocessor modules are available in configurations supporting 32 or
128 contexts. A single context refers to a compression and
decompression for a single PPP circuit or Frame Relay
VC. Additionally, hardware- and software-based compression can be
combined during configuration to provide a combined total of over 200
dictionaries.
The hardware- and software-based Data Compression offerings use Bay
Networks compression protocol -- WAN Com-pression Protocol (WCP) -- to
enable reliable transport of compressed data over Frame Relay and PPP
connections. WCP provides end-to-end error control to ensure proper
communications, keeping dictionaries synchronized between source and
destination routers. The draft RFC Compression Control Protocol (CCP)
to enable or disable compression for PPP is also supported.
Additionally, support for Continuous Packet Compression (CPC) mode
and Packet-by-Packet Compression (PPC) mode is provided. CPC yields a
higher compression rate and is used for maximum throughput. CPC mode
maintains a compression history across packet boundaries and requires
that the histories at each end of the link be synchronized through a
reliable data link protocol. PPC mode resets the history for each
packet and does not require a reliable data link protocol.
Traffic Prioritization Traffic Prioritization filters can
assign a high priority to time-sensitive and/or mission-critical
traffic,reducing the occurrence of session timeouts and improving
application response times. Priority filters can be configured that
place packets into one of three priority queues -- high, normal, or
low -- for transmission through an outbound serial interface of a Bay
Networks router. Priority filters can be applied to all network and
bridging protocols supported by Bay Networks routers.
Priorities can be assigned to packets based on their protocol,
source network, destination network, packet type, and other
protocol-specific fields, as well as other fields that are
identifiable by an offset in a packet. The number of priority filters
defined for a protocol on an interface is user-definable.
Traffic Prioritization can be configured to use either a strict
dequeuing algorithm or a bandwidth allocation dequeuing algorithm to
transmit packets across a serial line. Bay Networks strict dequeuing
algorithm transmits all packets from the high-priority queue before
transmitting packets from the normal and low-priority queues. The
bandwidth allocation dequeuing algorithm allows packets from the
normal and low-priority queues to be transmitted when the
high-priority queue still contains packets, based on user-assigned
bandwidth allocation percentages for each queue. This ensures that
packets assigned lower priorities are transmitted in environments with
large amounts of high-priority traffic.
Uniform Traffic Filters Uniform Traffic Filters enables
inbound and outbound traffic filters to be easily established for all
network and bridge protocol traffic. Uniform Traffic Filters provides
an efficient method for developing an effective and comprehensive
network security strategy. In addition, Uniform Traffic Filters
preserves WAN bandwidth and can increase performance by reducing
network congestion.
Inbound traffic filters can be configured to accept or drop
incoming packets from any local area or serial network interface in a
Bay Networks router. Outbound traffic filters can be configured to
drop outgoing packets destined for any Bay Networks router serial
interface. Additionally, Uniform Traffic Filters can be configured to
execute a log action when a datagram's fields match the values defined
in the filter.
Filters can be created using predefined protocol-specific fields or
user-defined fields. Up to 31 inbound filters and 31 outbound filters
(including Traffic Prioritization filters) can be defined for each
protocol on every supported network interface. Filter precedence can
be configured on an interface, reducing filter definition
complexity. All filters are configured via Bay Networks router
management application, Optivity Internetwork™.
IP RIP/OSPF/Static Equal Cost Multipath Support Bay
Networks routers support of IP RIP and OSPF Equal Cost Multipath
enables multipacket transmissions with the same destination to be
forwarded over multiple equal-cost paths using a round-robin
forwarding or address-based forwarding algorithm. This enables sites
to select a forwarding technique that makes the most efficient use of
available bandwidth and is best suited for the type of traffic on the
internetwork. Round-robin forwarding dynamically forwards packets over
all equal cost paths evenly. This enables sites to take advantage of
the aggregate bandwidth available. Address-based forwarding captures
source and destination addressing as packets are forwarded and
consistently forwards packets with matching addresses over the same
interface. This ensures client-to-server connectivity by eliminating
out-of-order packet delivery for time-sensitive applications.
Multiline Circuits Multiline Circuits allows a single
circuit to be composed of up to 16 individual serial network data
paths, ensuring circuit availability in the event of a single data
path failure. Multiline Circuits also increases bandwidth between two
sites without the circuit management complexities associated with
multiple circuits. Following initial configuration, the use of
multiple data paths to form a single circuit is completely
transparent.
Multiline Circuits provides two methods for transmitting traffic
over its data paths -- address-based selection and random
selection. Address-based selection determines the path a packet takes
based on its source and destination addresses, ensuring the
sequentiality of packets. Random selection determines the path each
packet takes based on a randomly assigned number, which corresponds to
a particular data path in the circuit. This provides for even
distribution across the circuit.
Network Management
Bay Networks offers a complete SNMP-based, enterprise management
solution for any environment. As members of Bay Networks OptivityŠ
family of network management products, UNIX-based Optivity
Internetwork, and Windows-based Optivity Campus™ and EZ
Internetwork™ are powerful tools for providing comprehensive node
configuration, monitoring, and control.
Optivity Internetwork A component of Bay Networks
UNIX-based Optivity Enterprise™ application suite, Optivity
Internetwork provides a sophisticated, yet easy-to-use management
solution for complex router-based internetworks. Optivity Internetwork
simplifies and improves management of complex router internetworks by
integrating ControlCenter™, the revision control system for Bay
Networks routers; Site Manager, the node management application for
Bay Networks routers; RouterMan™, an intuitive router monitoring
application; and PathMan™, a graphical network diagnostic
tool.
Optivity Internetwork operates with the leading SNMP platforms --
HP OpenView, Tivoli NetView for AIX, and Sun Microsystem's Solstice
Domain Manager for additional capabilities.
Optivity Campus Bay Networks provides two Windows-based
network management applications that enable Ethernet and Token Ring
networks to be managed from a central platform -- Optivity Campus for
Novell ManageWise and Optivity Campus for HP OpenView (Windows). These
applications offer a wide range of features for managing shared media,
frame-switched, and routed networks.
Optivity Campus contains the Autotopology™ dynamic mapping
feature, which automatically discovers and displays all hubs, bridges,
switches, routers, and endstations to create an accurate blueprint of
the network configuration. Optivity Campus also includes applications
for managing particular network devices, including a Windows-based
version of RouterMan (see the "Optivity Internetwork" section) and
Quick2Config, that allows Bay Networks routers to be configured and
operational in minutes.
Quick2Config™ is a Windows-based application that allows
configuration files to be created or modified quickly and easily via
its intuitive graphical user interface (GUI) that hides the underlying
complexities of router configuration.
Designed for medium-sized networks, Optivity Campus for ManageWise
enables NetWare systems in IPX-only and mixed IP/IPX networks to be
managed from a single console. Optivity for NetWare ManageWise
operates in a client/server arrangement requiring a DOS/Windows
station and a NetWare server.
Optivity Campus for HP OpenView (Windows) provides a
standards-based system for managing mid- to large size networks. Based
on a DOS/Windows architecture, this application provides seamless
integration with HP's OpenView for Windows network management platform
to allow shared access and frame switched networks to be managed from
a single console.
EZ Internetwork A component of the DOS/Windows-based
Optivity Workgroup™ application suite, EZ Internetwork provides a
comprehensive set of network management capabilities accessible
through a point-and-click, Windows-based user interface for the Bay
Networks ASN, and BayStack Access Node (ANŠ), and Access Node Hub
(ANH™) routers. EZ Internetwork integrates Quick2Config (see the
"Optivity Campus" section), with a Windows-based version of RouterMan
(see the "Optivity Internetwork" section).
Standards
The IP implementation described in this data sheet supports major
IETF RFCs, as shown in Table 1.
Table 1 | IETF IP RFC Support
| RFC Number |
Description |
| 768 |
User Datagram Protocol (UDP) |
| 783 |
Trivial File Transfer Protocol (TFTP) |
| 791 |
Internet Protocol (IP) |
| 792 |
Internet Control Message Protocol (ICMP) |
| 793 and 1323 |
Transmission Control Protocol (TCP) |
| 826 |
Address Resolution Protocol (ARP) |
| 854 |
Virtual Terminal Protocol (Telnet) |
| 877 and 1356 |
IP over X.25 Networks |
| 903 |
Reverse Address Resolution Protocol (RARP) |
| 904 |
Exterior Gateway Protocol (EGP) Version 2 |
| 950 |
Internet Subnetting Procedures |
| 951 |
Bootstrap Protocol (BootP) |
| 1001 |
Protocol Standard for a NetBIOS Service on a TCP/UDP Transport: Concept and Methods |
| 1002 |
Protocol Standard for a NetBIOS Service on a TCP/UDP Transport: Detailed Specifications |
| 1009 |
Internet Gateway Requirements |
| 1042 |
IP over IEEE 802 Networks |
| 1058 |
Routing Information Protocol (RIP) |
| 1063 |
Maximum Transmission Unit Discovery Option |
| 1075 |
Distance Vector Multicast Routing Protocol (DVMRP) |
| 1084 |
BootP Vendor Extensions |
| 1108 |
Revised Internet Protocol Security Option (RIPSO) |
| 1112 |
Internet Group Management Protocol |
| 1155 |
Structure and Identification of Management Information |
| 1156 |
Internet Management Information Base |
| 1157 |
Simple Network Management Protocol (SNMP) |
| 1188 |
IP over FDDI |
| 1247 |
Open Shortest Path First (OSPF) Version 2 |
| 1256 |
Router Discovery |
| 1267 |
Border Gateway Protocol (BGP) Version 3 |
| 1519 |
Classless Interdomain Routing (CIDR) |
| 1532 |
Clarification's and Extension to BootP for the Bootstrap Protocol |
| 1533 |
DHCP Options and BootP Vendor Extensions |
| 1542 |
Clarification's and Extension to BootP for DHCP |
| 1654 |
BGP Version 4 |
Glossary
Selected network terminology is listed in Table 2.
Table 2 | IP Glossary
| Adjacency |
A relationship formed between selected neighboring routers for the purpose of exchanging routing information. Not every pair of neighboring routers becomes adjacent. |
| Autonomous System (AS) |
A group of routers under the administrative control of one authority. |
| Designated Router |
Each multiaccess network that has at least two attached routers has a Designated Router. Elected by the Hello Protocol, the Designated Router generates a link state advertisement for the multiaccess network and has other special responsibilities in the running of the protocol. The Designated Router concept the amount of routing protocol traffic and the size of the topological database. |
| Hello Protocol |
The part of the OSPF protocol used to establish and maintain neighbor relationships. On multiaccess networks, the Hello Protocol can also dynamically discover neighboring routers. |
| Interior Gateway |
The routing protocol spoken by the routers belonging to an Autonomous Protocol System. Each Autonomous System has a single IGP. Separate Autonomous Systems may be running different IGPs. |
| IP Address |
A 32-bit number representing the address of an internet device. |
| Link State Advertisement |
Describes the local state of a router or network, including the state of the router's interfaces and adjacencies. Each link state advertisement is flooded throughout the routing domain. The collected link state advertisements of all routers and networks forms the protocol's topological database. |
| Multiaccess Networks |
Physical networks that support the attachment of multiple (more than two) routers. Each pair of routers on such a network is assumed to be able to communicate directly (for example, multidrop networks are excluded). |
| Multicasting |
Delivery of packets from a single source to multiple simultaneous destinations, with the network duplicating the packets only when necessary. |
| Neighboring Routers |
Two routers that have interfaces to a common network. On multiaccess networks, neighbors are dynamically discovered by OSPF's Hello Protocol. |
| Network Mask |
A 32-bit number indicating the range of IP addresses residing on a single IP network/subnet/supernet. |
| Quality of Service (QoS) |
A service level required by an application usually described in a network by delay, bandwidth, and jitter. |
| Router ID |
A 32-bit number assigned to each router running the OSPF protocol. This number uniquely identifies the router within an Autonomous System (AS). |
| Resource Reservation |
The process of reserving network and host resources to achieve a quality of service (QoS) for an application. |
MIB Information
The IP MIB defines a number of "objects" or variables to be
monitored, as described in Table 3.
Table 3 | IP MIB
|
Object |
Description |
| 1 |
IP_create/delete |
Indicates whether the IP interface has been created (1) or deleted (2) |
| 2 |
IP_enable/disable |
Indicates whether the IP interface has been enabled (1) or disabled (2) |
| 3 |
IP_state |
Indicates current state of IP: up (1), down (2), initialized (3), invalid (4), or not present (5) |
| 4 |
IP_addr |
Identifies the IP address this entry's addressing information pertains to |
| 5 |
IP_interface_circuit |
Identifies the circuit number that this interface operates over |
| 6 |
IP_interface_mask |
Identifies the subnet mask associated with the IP address of this entry |
| 7 |
IP_interface_cost |
Indicates the cost associated with this IP interface |
| 8 |
IP_interface_cfg_bcastaddr |
Identifies the specified IP broadcast address used for sending datagrams on this interface |
| 9 |
IP_interface_bcastaddr |
Identifies the broadcast address for sending datagrams on this interface |
| 10 |
IP_ interface_mtu_discovery |
Indicates whether the MTU discovery option is On (1) or Off (2) |
| 11 |
IP_interface_amr |
Indicates whether the address mask reply is On (1) or Off (2) |
| 12 |
IP_interface_addr_res_type |
Indicates which address resolution type is being used: ARP (1), probe (2), X.25 DDN (3), X.25 PDN (4), INARP (5), or ARPINARP (6) |
| 13 |
IP_interface_asb |
Indicates whether all subnet broadcasts are accepted and transmitted from this interface |
| 14 |
IP_interface_proxy |
Indicates whether the interface has proxy ARP On (1) or Off (2) |
| 15 |
IP_interface_host_cache |
Indicates whether the host cache (address aging) is Off (1) or states aging time; range is from 120 to 1,200 seconds |
| 16 |
IP_interface_udp_xsum |
Indicates whether the UDP checksum verification is On (1) or Off (2) |
| 17 |
IP_interface_cfg_mac_addr |
Identifies the user-configured MAC address of interface |
| 18 |
IP_interface_mac_address |
Identifies the actual MAC address of the interface |
| 19 |
IP_interface_reasm_max_size |
Indicates the size of largest IP datagram that can be reassembled |
| 20 |
IP_interface_max_info |
Indicates the maximum size of the non-MAC info field |
| 21 |
IP_interface_in_receives |
Indicates the total number of IP datagrams received from interface |
| 22 |
IP_interface_in_hdr_errors |
Indicates the number of input datagrams discarded due to error in header |
| 23 |
IP_interface_in_addr_errors |
Indicates the number of input datagrams discarded because of an invalid IP address |
| 24 |
IP_interface_forw_datagrams |
Indicates the number of input datagrams forwarded by router |
| 25 |
IP_interface_in_unknown_proto |
Indicates the number of locally addressed datagrams discarded because of an unknown or unsupported protocol |
| 26 |
IP_interface_in_discards |
Indicates the number of input datagrams discarded due to lack of buffer space |
| 27 |
IP_interface_in_delivers |
Indicates the total number of input datagrams successfully delivered |
| 28 |
IP_interface_ out_requests |
Indicates the total number of IP datagrams supplied in response to requests for transmission |
| 29 |
IP_interface_out_discards |
Indicates the number of output IP datagrams discarded due to lack of buffer space |
| 30 |
IP_interface_out_no_routes |
Indicates the number of IP datagrams discarded because no routes could be found |
| 31 |
IP_interface_reasm_timeout |
Indicates the maximum number of seconds an interface can hold received fragments before it reassembles the message |
| 32 |
IP_interface_reasm_reqds |
Indicates the number of IP fragments received |
| 33 |
IP_interface_reams_ok |
Indicates the number of IP datagrams successfully reassembled |
| 34 |
IP_interface_reasm_fails |
Indicates the number of failures detected by the IP reassembly algorithm |
| 35 |
IP_interface_frags_ok |
Indicates the number of input datagrams successfully fragmented |
| 36 |
IP_interface_frag_fails |
Indicates the total number of input datagrams that could not be fragmented |
| 37 |
IP_interface_frag_creates |
Indicates the number of IP fragments generated |
| 38 |
IP_interface_icmp_in_msgs |
Indicates the total number of ICMP messages |
| 39 |
IP_interface_icmp_in_errors |
Indicates the number of ICMP messages with errors |
| 40 |
IP_interface_icmp_in_dest_unrc |
Indicates the number of ICMP "destination unreachable" messages received |
| 41 |
IP_interface_icmp_in_param_prb |
Indicates the number of ICMP "parameter problem" messages received |
| 42 |
IP_interface_icmp_time_exced |
Indicates the number of ICMP "time exceeded" messages received |
| 43 |
IP_interface_icmp_src_quench |
Indicates the number of ICMP "source quench" messages received |
| 44 |
IP_interface_icmp_redirects |
Indicates the number of ICMP "redirect" messages received |
| 45 |
IP_interface_icmp_echo |
Indicates the number of ICMP "echo" messages received |
| 46 |
IP_interface_icmp_echo_reps |
Indicates the number of ICMP "echo reply" messages received |
| 47 |
IP_interface_icmp_in_timestmp |
Indicates the number of ICMP "timestamp" messages received |
| 48 |
IP_interface_icmp_tmstmp_reps |
Indicates the number of ICMP "timestamp reply" messages received |
| 49 |
IP_interface_icmp_in_addr_msk |
Indicates the number of address mask requests received |
| 50 |
IP_interface_icmp_add_msk_rep |
Indicates the number of address mask reply messages received |
| 51 |
IP_interface_icmp_out_message |
Indicates the total number of ICMP messages that this interface attempted to send |
| 52 |
IP_interface_icmp_out errors |
Indicates the number of ICMP messages not sent due to problems |
| 53 |
IP_interface_icmp_out_dest_unr |
Indicates the total number of ICMP "destination unreachable" messages sent |
| 54 |
IP_interface_icmp_out_time_exc |
Indicates the number of ICMP "time exceeded" messages sent |
| 55 |
IP_interface_icmp_out_parm_pb |
Indicates the total number of ICMP parameter problem messages sent |
| 56 |
IP_interface_icmp_out_src_qunc |
Indicates the total number of ICMP "source quench" messages sent |
| 57 |
IP_interface_cache_removes |
Indicates the number of networks that have been flushed from cache due to aging |
| 58 |
IP_interface_cache_networks |
Indicates the total number of entries in the cache |
Operation
A set of IP-specific parameters must be configured for each
interface supporting IP, as shown in Table 4.
Table 4 | IP Configuration Parameters
| Parameter |
Function |
Action |
| Enable |
Enables/disables IP routing on this interface. |
Default is Enable; set to Disable to deactivate IP routing on this interface. |
| Subnet Mask |
Specifies the network and subnet portion of the 32-bit IP address. |
Enter the subnet mask for the class of the network
connected to this interface in dotted decimal notation. |
| Broadcast Address |
Specifies the broadcast address that the IP router uses to broadcast packets. |
Set to 0 to configure the IP router to use an all-1s address; optionally, enter the desired address in dotted decimal notation. |
| Interface Cost |
Specifies the cost of the interface. |
Default is 1; optionally, enter value to 16. |
| MTU Discovery |
Specifies whether the Maximum Transmission Unit reply option is enabled on the interface. |
Default is Off; set to On to enable this interface to respond to probe MTUs. |
| Addr Mask Reply |
Specifies whether this interface generates ICMP address-mask-reply messages address-mask-reply messages. |
Default is On; set to Off to disable ICMP responding to valid request messages. |
| All Subnet Bcast |
Specifies if the IP router floods received ASB datagrams across this interface. |
Default is On; set to Off to prohibit ASB flooding on this interface. |
| Address Resolution |
Specifies whether this interface uses ARP to map 32-bit IP addresses to 48-bit Ethernet. |
Default is Enable; set to Disable to disable ARP on this interface/address. |
| Proxy |
Specifies whether this interface uses proxy ARP. |
Default is Off; set to On to enable to respond to
ARPs for a remote network. Proxy ARP on this interface. |
| Host Cache |
Specifies whether the IP router ages entries in
the interface's address-resolution cache and specifies the aging interval in seconds. |
Default is 1 (Off); optionally set to 120, 180, 200, 240, 300, 600, 900, or 1,200. |
| Checksum |
Specifies whether UDP checksum processing is enabled on this interface. |
Default is On; set to Off to disable UDP checksum processing. |
| MAC Address |
Specifies a MAC address for this interface. |
Enter 0 to have router use its IP address and circuit's MAC address. |
System Requirements
Bay Networks IP implementation described in this data sheet is
currently included in BayRS Version 11.x for the Bay Networks Access
Node (AN), Access Node Hub (ANH), Access Feeder Node (AFN™), Access
Stack Node (ASN), Feeder Node (FN™), Link Node (LNŠ),
Concentrator Node (CNŠ), Backbone Link Node (BLNŠ), and Backbone
Concentrator Node (BCNŠ).
Ordering Information
IP is available in a variety of BayRS software options for the Bay
Networks AN, ANH, Advanced Remote Node (ARN™), ASN, System 5000
Router Module, BLN, BCN, LN, and CN as listed in Table 5.
Table 5 | BayRS Software
| Model Number |
Description |
| AE0008032 |
AN/ANH BayRS for IP Access for 4 MB Flash |
| AE0008033 |
AN/ANH BayRS for Remote Office for 4 MB Flash |
| AE0008034 |
AN/ANH BayRS for Corporate Suite for 4 MB Flash |
| AE0008036 |
AN/ANH BayRS for IP Access for 8 MB Flash |
| AE0008037 |
AN/ANH BayRS for Remote Office for 8 MB Flash |
| AE0008038 |
AN/ANH BayRS for Corporate Suite for 8 MB Flash |
| CV0008001 |
ARN BayRS for IP Access for 4 MB Flash |
| CV0008002 |
ARN BayRS for Remote Office for 4 MB Flash |
| CV0008003 |
ARN BayRS for Corporate Suite for 4 MB Flash |
| CV0008004 |
ARN BayRS for IP Access for 8 MB Flash |
| CV0008005 |
ARN BayRS for Remote Office for 8 MB Flash |
| CV0008006 |
ARN BayRS for Corporate Suite for 8 MB Flash |
| AF0008022 |
ASN BayRS for Basic software suite for 4 MB Flash |
| AF0008017 |
ASN BayRS for Basic software suite for 8 MB Flash |
| AF0008018 |
ASN BayRS for LAN software suite for 8 MB Flash |
| AF0008019 |
ASN BayRS for WAN software suite for 8 MB Flash |
| AF0008020 |
ASN BayRS for Corporate software suite for 8 MB Flash |
| AD0008014 |
System 5000 Router Module BayRS for System software suite for 4 MB Flash |
| AD0008009 |
System 5000 Router Module BayRS for System software suite for 8 MB Flash |
| AD0008010 |
System 5000 Router Module BayRS for LAN software suite for 8 MB Flash |
| AD0008011 |
System 5000 Router Module BayRS for WAN software suite for 8 MB Flash |
| AD0008012 |
System 5000 Router Module BayRS for Corporate software suite for 8 MB Flash |
| AG0008017 |
BLN/BCN BayRS for Basic software suite |
| AG0008018 |
BLN/BCN BayRS for LAN software suite |
| AG0008019 |
BLN/BCN BayRS for WAN software suite |
| AG0008020 |
BLN/BCN BayRS for Corporate software suite |
| 42020V###* |
LN/CN Corporate Suite |
| *### = Software version number(e.g., Version 11.0 =110). |