Configuring Eigrp Stub Routing - Cisco 3845 - Security Bundle Router Software Manual

Chapter 29 Configuring IP Unicast Routing
Configuring EIGRP

Configuring EIGRP Stub Routing

The EIGRP stub routing feature reduces resource utilization by moving routed traffic closer to the end
user. 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.
Note EIGRP stub routing only advertises connected or summary routes from the routing tables to other
switches in the network. The switch uses EIGRP stub routing at the access layer to eliminate the need
for other types of routing advertisements. If you try to configure multi-VRF-CE and EIGRP stub routing
at the same time, the configuration is not allowed.
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 29-4, 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 29-4 EIGRP Stub Router Configuration
Routed to WAN
Switch A Switch B Switch C
Host A Host B Host C
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 from the Cisco.com
page under Documentation > Cisco IOS Software > 12.2 Mainline > Configuration Guides.
Cisco ME 3800X and 3600X Switch Software Configuration Guide
29-39
OL-23400-01