Balaji R (Networking) - CTD, Chennai. wrote:
> Hello,
>
> I have a question regarding the association of neighbor data structure with
> a received hello packet.
>
> Section 10.5 states that the neighbor is identified by the source IP address
> on all types of networks except point-to-point links. In point-to-point
> links, router ID found in the OSPF header must be used to locate the
> neighbor.
>
> My implementation maintains neighbors on a per-interface basis and knows the
> interface through which the packet came in. My question is, is there any
> issue in using the source IP address to locate the neighbor as is done in
> other types of networks? Are there any implications in doing so? (Actually,
> on numbered ptp links, we would have to check if the source IP address has
> changed every time we receive a packet, since we originate router LSA with
> the neighbor's IP address. I guess we would have to re-originate a new LSA
> if the neighbor's IP address changed. So, I thought locating the neighbor
> based on source IP address would hanlde this case more easily.)

For P2P links, the link data in your router link contains your interface IP
address - not your neighbors. You should not have to originate a new router
LSA if your neighbor's IP address changes.

>
> I can understand that using router ID to identify the neighbor can present
> problems with respect to multi-homing in multi-access networks. However, I
> don't fully appreciate why router ID must be used in point-to-point links to
> identify neighbors.
>
> Thanks,
> Balaji.R.
>

--
Acee

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