OSPF summary-address

davegibelli · ‎04-03-2007

Hi

Why does the following not work?

router ospf 1

redistribute connected

summary-address 0.0.0.0 0.0.0.0

I expect OSPF to distribute a default route but instead OSPF stops announcing any routes!

Any ideas?

Harold Ritter · ‎04-03-2007

The only mean to inject the default route in an OSPF autonomous system is through the use of the command "default-information" originate.

Hope this helps,

Harold Ritter
Sr Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
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sundar.palaniappan · ‎04-03-2007

Dave,

The 'summary-address' command is used in ASBR, router connecting to an external AS, and I am guessing this router may be connected to your ISP.

If that's the case then just like Harold stated configure 'default-information originate' under your OSPF process and the router would continue to inject a default route as long as it has a default route in it's routing table.

HTH

Sundar

davegibelli · ‎04-03-2007

Sundar

With bgp you will not get a default route from a peer so there is no default route in your routing table in the first place.

I want to summarise all bgp routes into a default route and only inject this default into ospf if the bgp session is up...

davegibelli · ‎04-03-2007

How would I make a default injection conditional?

sundar.palaniappan · ‎04-03-2007

Can you elaborate what you are trying to do?

davegibelli · ‎04-03-2007

Sundar

I have two bgp routers, each has a single peering session. I want each bgp router to annouce a default route into ospf but only if the bgp session is up.

Sounds simple but I cannot figure out how!

sundar.palaniappan · ‎04-03-2007

Have a look at the last example in this link titled 'conditional default origination'.

http://cisco.com/en/US/products/sw/iosswrel/ps1826/products_configuration_guide_chapter09186a00800877d7.html

HTH

Sundar