notes: EIGRP Stub Routing

Often used in a hub-and-spoke topology. Only routes you specify are propagated from the stub router. The stub router responds to all queries with the message “inaccessible.” A router configured as a stub sends a special peer information packet to all neighboring routers to report its status as a stub router. Nonstub routers do not query stub routers. The stub routing feature does not prevent routes from being advertised to the stub router. You must configure the summarization or default route behavior.

- A router that has EIGRP stub neighbors will not send queries to those stubs, thereby eliminating the chance that a stub will cause stuck-in-active conditions, and routing instabilities in other parts of the network.
- Stub Routing can also be useful to prevent a router from being used as transit/backup by only sending local updates not containing remote learned routes.

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COMMANDS
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- With detail option: (CONNECTED SUMMARY) shows the configured STUB neighbors

show ip eigrp neighbors [detail]

- Configured on a stub router defining which routes to be sent
- DEFAULT: Only updates containing connected and summary routes will be sent
- Receive-Only]: The stub router will not send any route information in updates

eigrp stub [connected | redistributed | static | summary | receive-only]

stub (connected only)

router eigrp 100
eigrp stub connected

stub with leak-map

The leak-map feature of EIGRP stub, like the leak-map for EIGRP
summarization, allows the advertisement of routes that would normally be
suppressed.

ip prefix-list SW2_LOOPBACK seq 5 permit 150.1.8.0/24
!
route-map STUB_LEAK_MAP deny 10
match ip address prefix-list SW2_LOOPBACK
!
route-map STUB_LEAK_MAP permit 20
!
router eigrp 100
eigrp stub connected leak-map STUB_LEAK_MAP
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