Re: OSPF virtual-link-

Narbik , i have never heard of area fragmentation. what does it mean?

On Fri, Oct 5, 2012 at 6:25 AM, Narbik Kocharians <narbikk_at_gmail.com> wrote:

> oo IPX,
>
> The only area that can not be fragmented is area 0.
>
> On Thu, Oct 4, 2012 at 5:15 PM, oo IPX <oispxl_at_gmail.com> wrote:
>
> > 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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> >
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> >
> >
>
>
> --
> *Narbik Kocharians
> *CCSI#30832, CCIE# 12410 (R&S, SP, Security)
> *www.MicronicsTraining.com* <http://www.micronicstraining.com/>
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Received on Fri Oct 05 2012 - 13:59:02 ART