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EIGRP AS?

Hi,

I want to know if I use two diff. AS no. in EIGRP then cant communicate but in OSPF we can use two diff. Process ID then we can communicate??

1 ACCEPTED SOLUTION

Accepted Solutions
Hall of Fame Super Silver

Re: EIGRP AS?

Hello Abhinay,

your understanding is correct:

two EIGRP routers become neighbors if :

their EIGRP hello packets contain the same AS number and the same K values (used for EIGRP metric), same IP subnet

The two don't need to have matching timers.

With OSPF:

the OSPF process-id is an internal tag that allows Cisco routers to run multiple instances of OSPF with separated databases.

In OSPF version 2 the process-id is not exported in OSPF hello packets

to build an OSPF neighborship:

same area number, same area type, same timers (but they can have different OSPF cost on the interface)

in both protocols neighborship is built only on primary address not on secondary addresses and authentication type and password must match if used.

So EIGRP AS number is a domain-wide parameter.

Hope to help

Giuseppe

2 REPLIES
Hall of Fame Super Silver

Re: EIGRP AS?

Hello Abhinay,

your understanding is correct:

two EIGRP routers become neighbors if :

their EIGRP hello packets contain the same AS number and the same K values (used for EIGRP metric), same IP subnet

The two don't need to have matching timers.

With OSPF:

the OSPF process-id is an internal tag that allows Cisco routers to run multiple instances of OSPF with separated databases.

In OSPF version 2 the process-id is not exported in OSPF hello packets

to build an OSPF neighborship:

same area number, same area type, same timers (but they can have different OSPF cost on the interface)

in both protocols neighborship is built only on primary address not on secondary addresses and authentication type and password must match if used.

So EIGRP AS number is a domain-wide parameter.

Hope to help

Giuseppe

New Member

Excellent response.

Excellent response.

I need help on cisco labs and sims for new exam.

I am taking the Cisco CCNA 200-125 exam.

Need some help on looking at sims on test and determining best answer.

I have the following resources: E-book Cisco CCNAX, cisco labs with course. 9tut subscription and access to Transcender test prep

Need help on sims and labs, will pay someone to review with white board, remote access or best teaching method.

Thanks

Steven  

Pgh, Pa

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