ospf

[carl_townshend]

Hi all, I am reading my cisco ccna book, it mentions ASBR routers, how do you define an as in ospf ?

[royalblues]

Hi Carl,

The as# is appended to the router OSPF comamnd

Eg. router ospf 100

Regarding ASBR - These are the routers which pass on external routing information into the OSPF domain.

Eg. External routing information can be passed onto OSPF domain through redistribution

HTH, rate if it does

Narayan

[carl_townshend]

do you mean redistributing eigrp into ospf for example, and i believe the 100 is just a process number only relevant to the router not an as number

[royalblues]

yes you are correct.

The number you mention is just a process ID (and not excatly an AS) which acts as an identifier if you have multiple ospf process running on a single router.

The entire OSPF toplogy is considered to be under a common AS and hence the router which originates information about outside AS (say through rredistibution) is called as ASBR

HTH, rate if it does

Narayan

[carl_townshend]

so that way, an AS can only be when using another routing protocol ?

[royalblues]

Yes (in a way when working with OSPF)

Narayan