Table of Contents

Configuring Networking Protocols

This chapter describes networking protocol configurations for your switch router. It provides initial configuration information so you can get your switch router up and running.

This chapter includes the following sections:

About IP Routing Protocols

IP routing is enabled by default on the switch router. For IP routing, you must configure the following values on the interface:

You must also do the following global configurations:

Layer 3 switching supports the following routing protocols:

For more information on these routing protocols, see the Cisco  IOS IP and IP Routing Protocols Configuration Guide.

Note   Layer 3 switching does not support the Next Hop Resolution Protocol (NHRP).

Routing Information Protocol

Routing Information Protocol (RIP) is a distance-vector, intradomain routing protocol. RIP works well in small, homogeneous networks. However, in larger, more complex internetworks it has many limitations, such as a maximum hop count of 15, lack of support for variable-length subnet masks (VLSMs), inefficient use of bandwidth, and slow convergence. (RIP II does support VLSMs.)

For more detailed information on RIP, see the "Configuring RIP" chapter in the Cisco  IOS IP and IP Routing Protocols Configuration Guide.

Open Shortest Path First

Open Shortest Path First (OSPF) is a standards-based IP routing protocol designed to overcome the limitations of IP RIP. Because OSPF is a link-state routing protocol, it sends link-state advertisements (LSAs) to all other routers within the same hierarchical area. Information on the attached interfaces and their metrics is used in OSPF LSAs. As routers accumulate link-state information, they use the Shortest Path First (SPF) algorithm to calculate the shortest path to each node. Additional OSPF features include equal-cost multipath routing and routing based on the upper-layer type of service (ToS) requests.

OSPF employs the concept of an area, which is a grouping of contiguous OSPF networks and hosts. OSPF areas are logical subdivisions of OSPF autonomous systems whose internal topology is hidden to routers outside the area. Areas allow an additional level of hierarchy different from that provided by IP network classes, and they can be used to aggregate routing information and mask the details of a network. These features make OSPF particularly scalable to large networks.

For more detailed information on OSPF, see the "Configuring OSPF" chapter in the Cisco  IOS IP and IP Routing Protocols Configuration Guide.

Interior Gateway Routing Protocol

Interior Gateway Routing Protocol (IGRP) is a distance vector interior-gateway routing protocol developed by Cisco Systems. Distance vector routing protocols call for each other to send all or a portion of its routing table in a routing update message at regular intervals to each of its neighboring routers. As routing information proliferates through the network, routers can calculate distance to all the nodes within the internetwork. IGRP uses a combination of metrics: internetwork delay, bandwidth, reliability, and load are all factored into the routing decision.

For more detailed information on IGRP, see the "Configuring IGRP" chapter in the Cisco  IOS IP and IP Routing Protocols Configuration Guide.

Enhanced Interior Gateway Routing Protocol

Enhanced Interior Gateway Routing Protocol (EIGRP) is an enhanced version of IGRP that combines the advantages of link-state protocols with distance vector protocols. EIGRP incorporates the Diffusing Update Algorithm (DUAL). EIGRP includes features such as fast convergence, variable-length subnet masks, partial bounded updates, and multiple network-layer support.When a network topology change occurs, EIGRP checks its topology table for a suitable new route to the destination. If such a route exists in the table, EIGRP updates the routing table instantly.You can use the fast convergence and partial updates EIGRP provides to route IPX packets.

EIGRP saves bandwidth by sending routing updates only when routing information changes. The updates contain only information about the link that changed, not the entire routing table. EIGRP also takes into consideration the available bandwidth when determining the rate at which it transmits updates.

For more detailed information on EIGRP, see the "Configuring IP Enhanced IGRP" chapter in the Cisco  IOS IP and IP Routing Protocols Configuration Guide.

Border Gateway Protocol

Border Gateway Protocol (BGP) is an Exterior Gateway Protocol (EGP) that allows you to set up an interdomain routing system to automatically guarantee the loop-free exchange of routing information between autonomous systems. In BGP each route consists of a network number, a list of autonomous systems that information has passed through (called the autonomous system path), and a list of other path attributes.

Layer 3 switching supports BGP version 4, including classless interdomain routing (CIDR). CIDR lets you reduce the size of your routing tables by creating aggregate routes resulting in supernets. CIDR eliminates the concept of network classes within BGP and supports the advertising of IP prefixes. CIDR routes can be carried by OSPF, EIGRP, and RIP.

BGP also supports Multicast BGP (MBGP). MBGP allows you to have a unicast routing topology different from a multicast routing topology, giving more control over the network and network resources. For more information on MBGP, see the "Distance Vector Multicast Routing Protocol Interoperability" section.

For more detailed information on BGP, see the "Configuring BGP" chapter in the Cisco  IOS IP and IP Routing Protocols Configuration Guide.

Intermediate System-to-Intermediate System

Intermediate System-to-Intermediate System (IS-IS) is an OSI link-state hierarchical routing protocol that floods the network with link-state information to build a complete, consistent picture of the network topology. To simplify router design and operation, IS-IS distinguishes between Level 1 and Level 2 ISs. Level 1 ISs communicate with other Level 1 ISs in the same area. Level 2 ISs route between Level 1 areas and form an intradomain routing backbone. Hierarchical routing simplifies backbone design because Level 1 ISs only need to know how to get to the nearest Level 2 IS. The backbone routing protocol also can change without impacting the intra-area routing protocol.

For more detailed information on IS-IS, see the "Configuring Integrated IS-IS" chapter in the Cisco  IOS IP and IP Routing Protocols Configuration Guide.

Configuring IP Routing Protocols

This section briefly describes how to configure the switch router for supported IP routing protocols. It is intended to provide enough information for a network administrator to get the protocols up and running. However, this section does not provide in-depth configurations for each protocol. For detailed information, refer to any of the protocol configuration guides in the public domain and to the Cisco  IOS IP and IP Routing Configuration Guide.

Configuring RIP

To configure RIP routing, perform the following steps, beginning in global configuration mode:

Configuring RIP Routing

The following example shows how to configure RIP routing:

For more information on configuring RIP routing, refer to the "Configuring RIP" chapter in the Cisco  IOS IP and IP Routing Configuration Guide.

Verifying the RIP Configuration

To verify the RIP configuration, use the following EXEC command:

Example

The following example shows the RIP configuration:

Configuring OSPF

To configure OSPF routing, perform the following steps, beginning in global configuration mode:

Configuring OSPF Routing

The following example shows how to configure OSPF routing:

For more information on configuring OSPF routing, refer to the "Configuring OSPF" chapter in the Cisco  IOS IP and IP Routing Configuration Guide.

Verifying the OSPF Configuration

To verify the OSPF configuration, use the following EXEC command:

Displaying OSPF Configuration

The following example shows the OSPF configuration:

Configuring IGRP

To configure IGRP routing, perform the following steps, beginning in global configuration mode:

Configuring IGRP

The following example shows how to configure IGRP routing:

For more information on configuring IGRP routing, refer to the "Configuring IGRP" chapter in the Cisco  IOS IP and IP Routing Configuration Guide.

Verifying the IGRP Configuration

To verify the IGRP configuration, use the following EXEC command:

Displaying IGRP Configuration

The following example shows the IGRP configuration:

Configuring EIGRP

To configure EIGRP routing, perform the following steps, beginning in global configuration mode:

Configuring EIGRP

The following example shows how to configure EIGRP routing:

For more information on configuring EIGRP routing, refer to the "Configuring IP Enhanced IGRP" chapter in the Cisco  IOS IP and IP Routing Configuration Guide.

Verifying the EIGRP Configuration

To verify the EIGRP configuration, use the following EXEC command:

Displaying EIGRP Configuration

The following example shows the EIGRP configuration:

Configuring BGP

To configure BGP routing, perform the following steps, beginning in global configuration mode:

Configuring BGP Routing

The following example shows how to configure BGP routing:

For more information on configuring BGP routing, refer to the "Configuring BGP" chapter in the Cisco  IOS IP and IP Routing Configuration Guide.

Verifying the BGP Configuration

To verify the BGP configuration, use the following EXEC command:

Displaying BGP Configuration

The following example shows the BGP configuration:

Configuring IS-IS

To configure IS-IS routing, perform the following steps, beginning in global configuration mode:

Configuring IS-IS Routing

The following example shows how to configure IS-IS routing:

For more information on configuring IS-IS routing, refer to the "Configuring Integrated IS-IS" chapter in the Cisco  IOS IP and IP Routing Configuration Guide.

Verifying the IS-IS Configuration

To verify the IS-IS configuration, use the following EXEC command:

Displaying the IS-IS Configuration

The following example shows the IS-IS configuration:

Configuring Load Balancing

Load balancing based on equal-cost parallel paths is supported for all IP routing protocols. To configure load balancing for a routing protocol, perform the following steps, beginning in global configuration mode:

Configuring Load Balancing

The following example shows how to configure load balancing for BGP routing:

Monitoring IP Operation

Once IP routing is configured, you can monitor and troubleshoot the protocol operation using the following commands:

For more information on the commands, refer to the "IP Multicasting Routing Commands" chapter in the Cisco  IOS IP and IP Routing Command Reference publication.

About IP Multicast Routing

As networks increase in size, multicast routing becomes critically important as a means to determine which segments require multicast traffic and which do not. IP multicast is a routing technique that allows IP traffic to be propagated from one source to a number of destinations, or from many sources to many destinations. Rather than sending one packet to each destination, one packet is sent to the multicast group identified by a single IP destination group address.

A principal component of IP multicast is the Internet Group Management Protocol (IGMP). With IGMP, a class D address can dynamically register an individual host in a multicast group. Hosts identify their group membership by sending IGMP messages to the switch router. Traffic is sent to all members of a multicast group. A host can be a member of more than one group at a time. Also, a host does not need to be a member of a group to send data to that group. Enabling Protocol Independent Multicast (PIM) on an interface also enables IGMP operation on that interface.

IP multicast supports constrained multicast flooding over bridge group virtual interfaces (BVIs), as well as BVIs over Fast EtherChannel. Using constrained multicast flooding, the switch router can dynamically determine group membership of IP multicast groups and flood multicast packets only to those ports where group members reside.

For more information on IP multicast routing, refer to the Cisco  IOS IP and IP Routing Configuration Guide.

Supported IP Multicast Routing Protocols

Layer 3 switch routers support the following IP multicast routing protocols:

Protocol Independent Multicast

Protocol Independent Multicast (PIM) includes two different modes of behavior for dense and sparse traffic environments. These are referred to as dense mode and sparse mode.

PIM dense mode assumes that the downstream networks want to receive the datagrams forwarded to them. The switch router forwards all packets on all outgoing interfaces until pruning and truncating occurs.Thus, interfaces with PIM dense mode enabled receive the multicast data stream until it times out. PIM dense mode is most useful under these conditions:

PIM sparse mode assumes that the downstream networks do not want to forward multicast packets for a group unless there is an explicit request for the traffic. PIM sparse mode defines a rendezvous point, which is used as a registration point to facilitate the proper routing of packets.

When a sender wants to send data, it first sends the data to the rendezvous point. When a router is ready to receive data, it registers with the rendezvous point. After the data stream begins to flow from the sender to the rendezvous point and then to the receiver, routers in the data path optimize the path by automatically removing any unnecessary hops, including the rendezvous point.

PIM sparse mode is optimized for environments in which there are many multipoint data streams and each multicast stream goes to a relatively small number of LANs in the internetwork. PIM sparse mode is most useful under these conditions:

For more information on PIM, refer to the "Configuring IP Multicast Routing" chapter in the Cisco  IOS IP and IP Routing Configuration Guide.

Distance Vector Multicast Routing Protocol Interoperability

Distance Vector Multicast Routing Protocol (DVMRP) interoperability uses a reverse path flooding technique to form multicast routes. The Layer 3 switch routers support interoperability with routers configured for DVMRP, but do not support a full DVMRP implementation. Layer 3 switch routers can send and receive DVMRP routing updates and can be configured to tunnel as DVMRP does, but do not run the actual routing protocol. Layer 3 switch routers forward multicast packets that have been forwarded by DVMRP routers and, in turn, forward multicast packets to DVMRP routers.

For more information on DVMRP interoperability, refer to the "Configuring IP Multicast Routing" chapter in the Cisco  IOS IP and IP Routing Configuration Guide.

Multicast Source Discovery Protocol

Multicast Source Discovery Protocol (MSDP) allows a switch router to connect multiple PIM sparse mode domains. MSDP makes multicast sources for a group to be known to all rendezvous points in different domains. Each PIM sparse mode domain uses its own rendezvous points and does not need to depend on rendezvous points in other domains. A rendezvous point runs MSDP over TCP to discover multicast sources in other domains.

A rendezvous point in a PIM sparse mode domain has a MSDP peering relationship with MSDP-enabled routers in other domains. The peering relationship occurs over a TCP connection, where a list of sources sending to multicast groups is exchanged. The underlying routing system makes TCP connections between rendezvous points. The receiving rendezvous point uses the source lists to establish a source path.

This topology enables domains to discover multicast sources in other domains. If the multicast sources interest a domain that has receivers, multicast data is delivered over the normal, source-tree building mechanism in PIM sparse mode domain.

MSDP is also used to announce sources sending to a group. These announcements must originate at the domain's rendezvous point.

When MSDP is configured, the following sequence occurs. The first data packet for source is registered by the first-hop router and that same data packet is decapsulated by the rendezvous point and forwarded down the shared tree. The packet is reencapsulated in a Source-Active (SA) message which is immediately forwarded to all MSDP peers. The SA message identifies the source, the group destination, the rendezvous point address or the originator ID, if configured. If the peer is a rendezvous point and contains a member of that multicast group, the data packet is decapsulated and forwarded down the shared-tree in the remote domain.

The PIM designated router directly connected to the source sends the data encapsulated in a PIM register message to the rendezvous point in the domain.

Note   This happens only once per source, when the source goes active. If the source times out, this process happens again when it goes active again. This process differs from the periodic SA message that contains all sources that are registered to the originating rendezvous point. These messages have no data.

Each MSDP peer receives and forwards the SA message away from the originating rendezvous point to achieve reverse-path forwarding (RPF) peer flooding. The concept of peer-RPF flooding relates to forwarding SA messages. The router examines the BGP or MBGP routing table to determine which peer is the next hop toward the originating rendezvous point of the SA message. Such a peer is called a Reverse-Path Forwarding peer (RPF). The router forwards the message to all MSDP peers other than the RPF peer. If the MSDP peer receives the same SA message from a non-RPF peer toward the originating rendezvous point, it drops the message. Otherwise, it forwards the message on to all its MSDP peers.

Note   MSDP depends heavily on MBGP for interdomain operation. We recommend that you run MSDP in rendezvous points in your domain for sources sending to global internet groups.

Multicast Border Gateway Protocol

Multicast Border Gateway Protocol (MBGP) adds capabilities to BGP that enables multicast routing policy throughout the internet and connects multicast topologies within and between BGP autonomous systems. That is, MBGP is an enhanced BGP that carries IP multicast routes. BGP carries two sets of routes, one set for unicast routing and one for multicast routing. PIM uses the routes associated with multicast routing to build data distribution trees.

You can use MBGP when you want a dedicated link to multicast traffic. Use the link to limit which resources are used for which traffic or to exchange all multicast traffic at one network access point. MBGP allows a unicast routing topology different from a multicast routing topology, which gives control over the network and network resources.

A multicast routing protocol, such as PIM, uses the MBGP routing table to perform Reverse Path Forwarding (RPF) lookups for multicast-capable sources. Thus, packets can be sent and accepted on the multicast topology but not on the unicast topology.

MBGP offers the following benefits:

Supported IP Multicast Functionalities

Layer 3 switch routers support the IP multicast features such as Cisco Group Management Protocol Server Functionality.

Cisco Group Management Protocol Server

IP multicasting consists of the transmission of IP traffic between source and destination. The multicast data is sent from the server to hosts that want to join the multicast transmission. Host groups have a Class D IP address and the server transmits one data stream to the entire host group at the same time in contrast to sending data streams to each host separately. The propagation of multicast traffic requires coordination amongst all network devices such as servers, hosts, routers, and switches.

To support IP multicasting services, all devices in a network must support Internet Group Management Protocol (IGMP). Cisco Group Management Protocol (CGMP) support is optional.

Note   The Layer 3 switch routers do not support IGMP snooping.

The Layer 3 switch routers support CGMP server functionality. When a host wants to join a multicast transmission, it sends a CGMP or IGMP join message to the server. In this join message the host specifies its MAC address and indicates the IP multicast group it wants to join. By sending the join message the host becomes a member of a multicast host group.

Similarly when a host wants to leave a multicast transmission, it sends an IGMP leave message to the server. The switch router with CGMP server functionality maintains the forwarding table for the members in a multicast group that it supports.

The IGMP capable switch router sends periodic multicast group queries. When a host wants to remain in a multicast group, it responds to the query. In this case, the router does nothing. If a host does not want to remain in the multicast group, it does not respond to the router query. If after a number of queries the switch router receives no reports from any host in a multicast group, the switch router removes the host from the multicast group and updates its forwarding table.

CGMP offers the following benefits:

Configuring IP Multicast Routing

To enable IP multicast routing, perform the following steps, beginning in global configuration mode:

Configuring IP Multicast Routing

The following example shows how to configure IP multicast routing:

Configuring PIM

To configure PIM on an interface, perform the following steps, beginning in global configuration mode:

Configuring Dense-mode PIM

The following example shows how to configure dense-mode PIM on an interface:

For more PIM configuration information and examples, refer to the "Configuring IP Multicast Routing" chapter in the Cisco  IOS IP and IP Routing Configuration Guide.

Configuring MSDP

Enable MSDP by configuring an MSDP peer to the local switch router. To configure an MSDP peer, use the following commands in global configuration mode:

The following example shows how to configure MSDP:

Configuring MSDP

For more MSDP configuration information, see the Cisco IOS IP and IP Routing Configuration Guide .

Configuring MBGP

To enable MBGP between two switch routers or routers, you must perform these tasks at a minimum on each switch router or router, beginning in global configuration mode:

Note   BGP must be configured to configure MBGP. See the "Configuring BGP" section 5-10 for configuration guidelines.

The following example shows how to configure MBGP on your switch router:

Configuring MBGP

To configure an MBGP peer group, perform the following steps:

The following example shows how to configure an MBGP peer group:

Configuring MBGP peer groups

For more MBGP configuration information, see the Cisco IOS IP and IP Routing Configuration Guide .

Other Advanced PIM Features

Use the following global configuration commands to configure advance PIM features:

Use the following interface configuration commands to configure advanced PIM features:

For more information on these features and commands, refer to the "Configuring IP Multicast Routing" chapter in the Cisco  IOS IP and IP Routing Configuration Guide, and the "IP Multicast Routing Commands" chapter in the Cisco  IOS IP and IP Routing Command Reference publication.

IP Unicast and IP Multicast Fragmentation

Your switch router supports IP unicast and IP multicast data packet fragmentation on the POS OC-12c uplink and ATM OC-3c and OC-12c uplink interfaces.

Monitoring IP Multicast Operation

Once IP multicast routing is configured, you can monitor and troubleshoot its operation. You can remove all contents of a particular cache, table, or database. You also can display specific statistics. The following sections describe each of these tasks.

Note   For information about Multicast Routing Monitor and other commands that monitor IP multicast information, see the chapter "Using IP Multicast Tools" in the Cisco  IOS IP and IP Routing Configuration Guide.

Clearing Caches, Tables, and Databases

You can remove all contents of a particular cache, table, or database. Clearing a cache, table, or database can become necessary when the contents of the particular structure have become, or are suspected to be, invalid.

To clear IP multicast caches, tables, and databases, use the following commands in EXEC mode:

For more information on these commands, refer to the "IP Multicasting Routing Commands" chapter in the Cisco  IOS IP and IP Routing Command Reference publication.

Displaying System and Network Statistics

You can display specific statistics such as the contents of IP multicast routing tables, caches, and databases. Information provided can be used to determine resource utilization and solve network problems. You can also display information about node reachability and discover the routing path your device packets are taking through the network.

To display various routing statistics, use the following commands in EXEC mode:

For more information on the commands, refer to the "IP Multicasting Routing Commands" chapter in the Cisco  IOS IP and IP Routing Command Reference publication.

Confirming Network Connectivity

To confirm the IP network connectivity, use the following command:

For more information on these commands, refer to the "IP Multicasting Routing Commands" chapter in the Cisco  IOS IP and IP Routing Command Reference publication.

About Novell IPX Protocol

The Cisco implementation of Novell Internetwork Packet Exchange (IPX) protocol provides all of the functionality of a Novell external bridge (Novell refers to their router functionality as bridging).

IPX is a proprietary protocol. Novell IPX can be described as follows:

Novell IPX uses the following protocols and services:

About IPX Network Addresses

An IPX network address consists of a network number and a node number, expressed in the format network.node.

Since both the network number and the host address are needed to deliver traffic to a host, addresses are usually given as network numbers, followed by host addresses, separated with dots, as in the example: 4a.0000.0c00.23fe. In this example, the network number is 4a, and the host address is 0000.0c00.23fe.

The serial interface does not have a MAC address. It uses the default Novell node address, which is the MAC address of the first activated interface.

About Global and Interface Parameters

To configure Novell IPX as a routing protocol, you must configure both global and interface parameters.

Global Configuration Parameters

To configure global parameters for Novell IPX routing, perform the following steps:

Step 2   Enable load sharing if appropriate for your network.

Load sharing divides routing tasks evenly among multiple routers to balance the work and improve network performance. Up to two parallel paths (six for the enhanced Gigabit Ethernet interfaces) are supported, with a default of one.

Once you have started IPX routing and enabled load sharing (if needed) on the router, you can configure the interface for Novell IPX routing.

Interface Configuration Parameters

To configure an interface for Novell IPX routing, perform the following steps:

You can assign multiple network numbers to an interface, allowing support of different encapsulation types. The IPX network number is the number of the Novell network to which the interface is attached. IPX packets received on an interface that does not have a network number are ignored.

Step 2   Set the optional encapsulation type, if it is different from the default.

The default encapsulation type for the switch router is novell-ether (Ethernet_802.3).

Note   This section does not describe IPX configuration in detail. Refer to the Cisco  IOS AppleTalk and Novell IPX Configuration Guide in the Cisco  IOS documentation set for detailed conceptual and configuration information.

Configuring Novell IPX Routing

To enable Novell IPX routing and configure an interface, perform the following steps, beginning in global configuration mode:

Configuring Novell IPX

The following example shows how to configure Novell IPX on FastEthernet interface 1/0/0:

For more information on configuring Novell IPX, refer to the "Configuring Novell IPX" chapter in the Cisco  IOS AppleTalk and Novell IPX Configuration Guide

Verifying the Novell IPX Configuration

To verify the Novell IPX configuration, use the following EXEC command:

Displaying Novell IPX Configurations

The following example shows the Novell IPX configuration of FastEthernet interface 1/0/0:

Monitoring Novell IPX Operation

The argument number is the number of the Novell network to which that interface is attached. Novell packets received on an interface that does not have a Novell network number are ignored.

Once IPX routing is configured, you can monitor and troubleshoot the protocol operation using the following commands:

Clearing Caches, Tables, and Databases

You can remove all contents of a particular cache, table, or database. Clearing a cache, table, or database can become necessary when the contents of the particular structure have become, or are suspected to be, invalid.

To clear Novell IPX tables, use the following commands in privileged EXEC mode:

For more information on these commands, refer to the "Novell IPX Commands" chapter in the Cisco IOS AppleTalk and Novell IPX Command Reference publication.

Displaying System and Network Statistics

You can display specific statistics such as the contents of IPX routing tables, caches, and databases. You can use the information provided to determine resource utilization and solve network problems. You can also display information about node reachability and discover the routing path your device packets are taking through the network.

To display various Novell IPX statistics, use the following commands in EXEC mode:

For more information on these commands, refer to the "Novell IPX Commands" chapter in the Cisco IOS AppleTalk and Novell IPX Command Reference publication.

Confirming Network Connectivity

The Cisco IOS software can send Cisco pings and standard Novell pings as defined in the NLSP specification or diagnostic request packets. By default, the software generates Cisco pings. To choose the ping type, use the following command in global configuration mode:

To confirm the Novell IPX network connectivity, use the following commands:

For more information on these commands, refer to the "Troubleshooting Commands" chapter in the Cisco IOS Configuration Fundamentals Command Reference publication.

About AppleTalk

AppleTalk refers to the Apple network protocol architecture. Layer 3 switching software supports AppleTalk Phase 1 and AppleTalk Phase 2. For AppleTalk Phase 2, Layer 3 switching software supports both extended and nonextended networks.

AppleTalk Enhanced IGRP provides automatic redistribution. By default, AppleTalk Routing Table Maintenance Protocol (RTMP) routes are automatically redistributed into Enhanced IGRP, and AppleTalk Enhanced IGRP routes are automatically redistributed into RTMP. If desired, you can turn off redistribution. You can also completely turn off AppleTalk Enhanced IGRP and AppleTalk RTMP either on the device or on its individual interfaces.

Interfaces that are configured for AppleTalk can be configured to use either RTMP, Enhanced IGRP, or both. If two neighboring routers are configured to use both RTMP and Enhanced IGRP, the Enhanced IGRP routing information supersedes the RTMP information; however, both routers continue to send RTMP routing updates. This feature allows you to control the excessive bandwidth usage of RTMP.

Apple Update-based Routing Protocol (AURP) can be enabled on a tunnel interface.

The AppleTalk protocol architecture requires that security measures be implemented at higher application levels. Layer 3 switching supports AppleTalk distribution lists, allowing control of routing updates on a per-interface basis.

To prevent any possible corruption of the AARP table in any AppleTalk node that is performing address gleaning through Media Access Control (MAC), Layer 3 switching AppleTalk does not forward packets with local source and destination network addresses.

Note   For more detailed information about AppleTalk, refer to the Cisco  IOS AppleTalk and Novell IPX Configuration Guide and the Cisco  IOS AppleTalk and Novell IPX Command Reference publication.

Configuring AppleTalk

To enable AppleTalk routing, first enable it on the router, and then configure it on each interface. All routers in a network or data link must agree on the cable range, default zone, and zone list. After an address and a zone name are assigned, the interface is enabled for packet processing.

To enable AppleTalk routing, perform the following steps, beginning in global configuration mode:

After you assign the address and zone names, the interface attempts to verify them with another operational router on the connected network. If there are any discrepancies, the interface does not become operational. If there are no neighboring operational routers, the device assumes the interface's configuration is correct, and the interface becomes operational.

Configuring AppleTalk

For more AppleTalk configuration information and examples, refer to the "Configuring AppleTalk" chapter in the Cisco  IOS AppleTalk and Novell IPX Configuration Guide.

Verifying the AppleTalk Configuration

Use the following EXEC command to verify the AppleTalk configuration:

Displaying AppleTalk Configuration

Monitoring AppleTalk Operation

Once your AppleTalk network is configured, you can monitor and troubleshoot its operation. You can remove all contents of a particular cache, table, or database. You also can display specific statistics. The following sections describe each of these tasks.

Clearing Caches, Tables, and Databases

You can remove all contents of a particular cache, table, or database. Clearing a cache, table, or database can become necessary when the contents of the particular structure have become, or are suspected to be, invalid.

To clear AppleTalk tables, use the following commands in privileged EXEC mode:

For more information on these commands, refer to the "AppleTalk Commands" chapter in the Cisco IOS AppleTalk and Novell IPX Command Reference publication.

Displaying System and Network Statistics

You can display specific statistics such as the contents of routing tables, caches, and databases. Information provided can be used to determine resource utilization and solve network problems. You can also display information about node reachability and discover the routing path your device packets are taking through the network.

To display various AppleTalk statistics, use the following commands in EXEC mode:

For more information on these commands, refer to the "AppleTalk Commands" chapter in the Cisco IOS AppleTalk and Novell IPX Command Reference publication.

Confirming Network Connectivity

To confirm the AppleTalk network connectivity, use the following commands:

For more information on these commands, refer to the "Troubleshooting Commands" chapter in the Cisco IOS Configuration Fundamentals Command Reference publication.