Re: OSPF virtual-link-

Thanks for quick answers. In-fact I was trying a virtual-link over an area
0, while trying making non-backbone area contiguous over a V-link (just for
curiosity), and got this error into debug that 'source ip address don't
match'. I guess over area 0 either its not supported or it behaves
differently, AS for sure the ios allows to use area 0 in the command
syntax, but how it deals with it later, i don't know :-)

And an interesting thing i noted, when using virtual link over a link in
area 0 with both endpoint on common sub-net is -- as soon as
one side is configured for the virtual link it starts sending hello packets
that don't contain the neighbor router-id, and as the source of the hello
packet is same over which the underlying peering is built on, the other
router jumps to INIT as soon as the hello packet that don't recognize this
router arrives.
But, I didn't notice this problem in same setup with non-backbone area.
I know its silly and not required, ( using a v link over backbone)

Can we source the hello packets from different address, not by using the
tunnels.

Thanks

On Fri, Oct 5, 2012 at 5:22 AM, Adam Booth <adam.booth_at_gmail.com> wrote:

> Even though the Cisco documentation is generally good , when it comes to
> base protocol operation, it's better to look at the RFC for the protocol,
> http://www.ietf.org/rfc/rfc2328.txt
>
> Section 15 second paragraph
>
> The virtual link is treated as if it were an unnumbered point-to-
> point network belonging to the backbone and joining the two area
> border routers. An attempt is made to establish an adjacency over
> the virtual link. When this adjacency is established, the virtual
> link will be included in backbone router-LSAs, and OSPF packets
> pertaining to the backbone area will flow over the adjacency
>
>
> virtual-links are configured on a router with the peer being the
> router-id, which is not necessarily an active IP address
>
>
>
>
> On Fri, Oct 5, 2012 at 9:16 AM, oo IPX <oispxl_at_gmail.com> wrote:
>
>> Hello,
>>
>> how the ospf peering comes up over a virtual link even when the source ip
>> address of the uni-cast hello are not on the same subnet ?
>>
>> Thanks.
>>
>>
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Received on Fri Oct 05 2012 - 05:45:33 ART