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Catalyst 3750 Switch Software Configuration Guide
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Chapter 35 Configuring IP Unicast Routing
Configuring EIGRP
In a network using EIGRP stub routing, the only allowable route for IP traffic to the user is through a
switch that is configured with EIGRP stub routing. The switch sends the routed traffic to interfaces that
are configured as user interfaces or are connected to other devices.
When using EIGRP stub routing, you need to configure the distribution and remote routers to use EIGRP
and to configure only the switch as a stub. Only specified routes are propagated from the switch. The
switch responds to all queries for summaries, connected routes, and routing updates.
Any neighbor that receives a packet informing it of the stub status does not query the stub router for any
routes, and a router that has a stub peer does not query that peer. The stub router depends on the distribution
router to send the proper updates to all peers.
In Figure 35-4, switch B is configured as an EIGRP stub router. Switches A and C are connected to the rest
of the WAN. Switch B advertises connected, static, redistribution, and summary routes to switch A and C.
Switch B does not advertise any routes learned from switch A (and the reverse).
Figure 35-4 EIGRP Stub Router Configuration
For more information about EIGRP stub routing, see “Configuring EIGRP Stub Routing” part of the
Cisco IOS IP Configuration Guide, Volume 2 of 3: Routing Protocols, Release 12.2.
Monitoring and Maintaining EIGRP
You can delete neighbors from the neighbor table. You can also display various EIGRP routing statistics.
Table 35-8 lists the privileged EXEC commands for deleting neighbors and displaying statistics. For
explanations of fields in the resulting display, see the Cisco IOS IP Command Reference, Volume 2 of 3:
Routing Protocols, Release 12.2.
Host A Host B
Switch B
Switch A
Routed to WAN
Switch C
Host C
145776
Table 35-8 IP EIGRP Clear and Show Commands
Command Purpose
clear ip eigrp neighbors [if-address | interface] Delete neighbors from the neighbor table.
show ip eigrp interface [interface] [as number] Display information about interfaces configured for EIGRP.
show ip eigrp neighbors [type-number] Display EIGRP discovered neighbors.