IGP - Default Route Summary

Default route
RIP

1. static route 0.0.0.0 to null 0, and the “network 0.0.0.0” command under the RIP process,
2. static route 0.0.0.0 to null 0, and the “redistribute static” command under the RIP process,
3. “default-information originate” command (advertises a default route even if a default route does not exist in the routing table / does not genarate null route, route feedback may occur), and
4. “ip default-network ...” command.

EIGRP

1. static route 0.0.0.0 to null 0, and the “network 0.0.0.0” command under the EIGRP process,
2. static route to 0.0.0.0, and the “redistribute static” command under the EIGRP process,
3. “ip summary-address 0.0.0.0 0.0.0.0 ...” command, and
4. “ip default-network ...” command.

OSPF

1. default-information originate always [route-map XXX] command (generates E2 route), and
2. using stub/nssa area.

Summary route:
RIP

1. ip summary-address rip <NETWORK> <MASK> (does not genarate null route, route feedback may occur).

EIGRP

1. ip summary-address eigrp <AS> <NETWORK> <MASK> [AD].

OSPF

1. area <AREA-ID> range <NETWORK> <MASK> [cost cost] (In ABR), and
2. summary-address <NETWORK> <MASK> [tag tag] (In ASBR).

Route filtering:
RIP

1. distribute-list,
2. offset-list,
3. distance,
4. tag, and
5. redistribution metric (close to 16).

EIGRP

1. distribute-list (route-map can be used to match tag or metric and also higher metric can be set by route-map),
2. offset-list,
3. distance,
4. maximum-hops,
5. tag,
6. redistribution metric (bandwidth, delay), and
7. eigrp stub receive-only/eigrp stub connected leak-map ...

OSPF
Local filtering:

1. distribute-list in ... (“distribute-list … out” command works only on ASBR),
2. distance ...,
3. route-map ..." (match interface / match ip address / match ip next-hop / match ip route-source / match metric / match route-type / match tag), and
4. ip ospf prefix-suppression / prefix-suppression.

LSA filtering:

1. area ... filter-list prefix ... (ABR),
2. area ... range ... not-adv (ABR),
3. summary-address … not-adv (ASBR),
4. ip ospf database-filter all out / neighbor … database-filter all out, and
5. max-metric router-lsa.

By Zakir A. Khan

*  IGP - Default Route  Summary .Pdf  | Download