simple question on OSPF: contents of the OSPF Hello message
aocferreira
Member Posts: 50 ■■■□□□□□□□
in CCNP
Hi guys,
According to cisco press book, below items are present in OSPF hello messages:
■ OSPF Router ID
■ Stub area flag
■ Plus the following interface-specific settings:
■ Hello interval
■ Dead Interval
■ Subnet mask
■ List of neighbors reachable on the interface
■ Area ID
■ Router priority
■ Designated Router (DR) IP address
■ Backup DR (BDR) IP address
■ Authentication digest
What do they mean with 'list of neighbors reachable on the interface' ?
If R1 sends hello packet to R2 through S0/0, only neighbor on that interface is R2... or it will be...
Am I getting this right?
According to cisco press book, below items are present in OSPF hello messages:
■ OSPF Router ID
■ Stub area flag
■ Plus the following interface-specific settings:
■ Hello interval
■ Dead Interval
■ Subnet mask
■ List of neighbors reachable on the interface
■ Area ID
■ Router priority
■ Designated Router (DR) IP address
■ Backup DR (BDR) IP address
■ Authentication digest
What do they mean with 'list of neighbors reachable on the interface' ?
If R1 sends hello packet to R2 through S0/0, only neighbor on that interface is R2... or it will be...
Am I getting this right?
Comments
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networker050184
Mod Posts: 11,962 Mod
Yep pretty much. But there are instances when a router will have multiple neighbors out of a single interface.An expert is a man who has made all the mistakes which can be made. -
aocferreira
Member Posts: 50 ■■■□□□□□□□
You are talking about frame relay topologies, for example? Yea it makes sense...
It was just to confirm as it was not making much sense to me that sentence
Thanks! -
networker050184
Mod Posts: 11,962 Mod
Not only frame relay, but also an ethernet segment which is much more common.An expert is a man who has made all the mistakes which can be made.
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Kory
Member Posts: 43 ■■□□□□□□□□
The other purpose of the field is to trigger a state change in the relationship. Because, when the router sees its own address in that neighbor field, it moves to 2-way state.