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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. For further information about the commands used in this chapter, refer to the command reference publications in the Cisco IOS documentation set and to "Command Reference."
This chapter includes the following sections:
The following global configurations are also required:
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.
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.
Table 5-1 shows an example of the Cisco IOS commands used to configure routing protocols to run on a Fast Ethernet interface.
| Step | Command | Purpose | ||
|---|---|---|---|---|
| Router(config)# interface fa x/0/z | From global configuration mode, enter Ethernet interface configuration mode to configure a particular Fast Ethernet interface. | ||
| Router(config-if)# ip address ip-address subnet-mask | |||
| Router(config-if)# exit | Exit interface configuration mode and step back one level to global configuration mode. | ||
| Router(config)# router rip
| Use the switch router rip command to define RIP as the routing protocol and start the RIP routing process. | ||
| Router(config-router)# network net-number | Use the network command to specify a directly connected network based on the Network Information Center (NIC) network number---not a subnet number or individual address. The routing process associates interfaces with the appropriate addresses and begins processing packets on the specified network. | ||
| Router(config-router)# exit | Return to global configuration mode. | ||
| Router# router igrp autonomous-system-number | Use the router igrp command to define IGRP as the IP routing protocol. The autonomous system number is the autonomous system to which this switch router belongs. | ||
| Router(config-router) # network net-number | Use the network command to define the directly connected networks that run IGRP. | ||
| Router(config-router)# exit | Return to global configuration mode. | ||
| Router(config)# router eigrp autonomous-system-number | Use the router eigrp command to define EIGRP as the IP routing protocol. The autonomous system number is the autonomous system to which this switch router belongs. | ||
| Router(config-router)# network net-number | Use the network command to define the directly connected networks that run EIGRP. The network number is the number of the network that is advertised by this switch router. | ||
| Router(config-router)# exit | Return to global configuration mode. | ||
| Router(config)# router ospf process-id | Use the router ospf command to define OSPF as the IP routing protocol. The process ID identifies a unique OSPF router process. This number is internal to the switch router only; the process ID does not have to match the process IDs on other routers. | ||
| Router(config-router)# network network-address wildcard-mask area area-id | Use the network area command to assign an interface to a specific area.
| ||
| Router(config-router)# Ctrl-Z | Return to privileged EXEC mode. | ||
| Router# copy running-config startup-config | Save your configuration changes to NVRAM. |
Once IP routing is configured, you can monitor and troubleshoot the protocol operation using the commands in Table 5-2.
| Command | Purpose |
|---|---|
show ip protocol | |
show ip route | Displays the contents of the IP routing table. The routing table contains entries for all known networks and subnetworks, and contains a code that indicates how that information was learned. |
show ip interfaces | Displays the status and global parameters associated with an interface. Cisco IOS automatically enters a directly connected route in the routing table if the interface is one through which a protocol can send and receive packets. Such an interface is marked "up." If the interface is unusable, it is removed from the routing table. |
debug ip rip | Displays RIP routing updates as the updates are sent and received. |
debug lss ipucast events | errors | reload | Displays pdates sent to the interface module for the IP switching control layer. |
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.
The routing protocols that the switch router uses to discover multicast groups and build routes for each group follow:
The Catalyst 8500 supports interoperability with routers configured for DVMRP.
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:
Table 5-3 shows an example of how to configure IP multicast routing.
| Step | Command | Purpose |
|---|---|---|
| 1 | Router(config)# ip multicast-routing | From global configuration mode, enable IP multicast on the switch router. |
| 2 | Router(config)# interface | Enter Ethernet interface configuration mode to configure the Fast Ethernet interface. |
| 3 | Router(config-if)# ip address ip-address subnet-mask | Assign an IP address and subnet mask to the interface. |
| 4 | Router(config-if)# ip pim [dense-mode | | |
| 5 | Router(config-if)# Ctrl-Z | Return to privileged EXEC mode. |
| 6 | Router# copy running-config startup-config | Save your configuration changes to NVRAM. |
Once IP multicast routing is configured, you can monitor and troubleshoot its operation using the commands in Table 5-4.
| Command | Displays |
|---|---|
show ip mroute | Complete multicast routing table |
show ip mroute count | Combined statistics of packets processed by the RP and the Ethernet interface modules |
debug lss ipmcast {events | errors | reload} | Updates sent to the interface module for the IP switching control layer |
IPX is a proprietary protocol. Novell IPX can be described as follows:
Novell IPX uses the following protocols and services:
network number A 4-byte (32-bit) number that identifies the physical network. The network number is expressed in hexadecimal and must be unique throughout the entire IPX internetwork. When configuring an IPX network number, you can omit the leading zeros.
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.
To configure global parameters for Novell IPX routing, follow these steps:
Step 1 Start the IPX routing process.
Step 2 Enable load sharing if appropriate for your network.
Once you have started IPX routing and enabled load sharing (if needed) on the router, you can configure the interface for Novell IPX routing.
To configure an interface for Novell IPX routing, follow these steps:
Step 1 Assign unique network numbers to each interface.
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).
Table 5-5 shows an example of how to enable Novell IPX routing, and configure an interface.
| Step | Command | Purpose |
|---|---|---|
| 1 | Router(config)# ipx routing | Enable Novell IPX routing and start the IPX routing process. If no node address is specified, the switch router uses the MAC address of the interface. |
| 2 | Router(config)# ipx maximum-paths | Allow load sharing over parallel metric paths to the destination. The maximum number of parallel paths is 2; the default number is 1. |
| 3 | Router(config)# interface | Enter Ethernet interface configuration mode to configure the Fast Ethernet interface. |
| 4 | Router(config-if)# ipx network number [encapsulation {type}] [secondary] | Each interface must have a unique hexadecimal IPX network number (up to 8 numbers in length). |
| 5 | Router(config-if)# Ctrl-Z | Return to privileged EXEC mode. |
| 6 | Router# copy running-config startup-config | Save your configuration changes to NVRAM. |
Once IPX routing is configured, you can monitor and troubleshoot the protocol operation using the commands in Table 5-6.
| Command | Purpose |
|---|---|
show ipx cache | Display the contents of the IPX fast-switching cache |
show ipx interfaces | Display the status and parameters of the interfaces configured for IPX |
show ipx interface fa x/0/z | Display the status and parameters for the specified Fast Ethernet IPX interface |
show ipx route | Display the contents of the IPX routing table |
show ipx servers | Display the list of IPX servers discovered through SAP advertisements, plus the network address, port number, and the number of hops and ticks to the server |
show ipx traffic | Display the number and type of IPX packets transmitted and received, as well as the number of broadcasts, SAPs, and routing packets received |
debug ipx routing activity | Turn on debugging information about RIP update packets |
debug ipx sap | Turn on debugging information about SAP update packets |
Refer to "Configuration Examples," for switch router configuration examples.
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.
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, use the procedure in Table 5-7.
| Step | Command | Description | ||
|---|---|---|---|---|
| Router(config)# appletalk routing router-number | Enable AppleTalk routing in the switch router with the default RTMP routing protocol. | ||
| Router (config)# interface | From the global configuration mode, enter Ethernet interface configuration mode to configure the Gigabit Ethernet interface. | ||
| Router(config-if)# appletalk cable-range range | |||
| Router(config-if)# appletalk zone name | Place the interface into a named zone. Multiple zone names can be assigned to one interface with AppleTalk 2. The first zone name is the default zone. | ||
| Router(config-if)# Ctrl-Z | Return to privileged EXEC mode. | ||
| Router# copy running-config startup-config | Save your configuration changes to NVRAM. |
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.
Now that you have configured the networking protocols for your switch router, see "Bridging Configurations."
Posted: Wed Dec 22 14:10:18 PST 1999
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