Hi Marko,

Thanks, but please help me in understanding more on this..

Suppose we have One PE router (Se0/0 is connected to customer A (VRF A),
Se0/1 is connected to customer B that is VRF B

When route (10.0.0.0/8)  hit on se0/0  from customer A router, PE router
will put those routes in VRF A routing table

and

when route (10.0.0.0/8) hit on se0/1 from customer B router, PE router will
put those routes in VRF B routing table.

and then finally MP-BGP will send those VPN prefixes to Remote PE router

and remote PE router will only just match RT and then will put into
corresponding VRFs.

So when we say RD keeps the prefixes unique by adding RD in front of it but
in what manner ?

we have RT that is also going along with it and on remote PE only RT is
checked  and on the remote end also customer A route 10.0.0.0/8 will be put
into VRF A by matching its RT and customer B route 10.0.0.0/8 will be put
into VRF B by mathcing its RT

So all the way along where is RD actually helping in keeping the routes
unique ?



On Fri, Jan 15, 2010 at 3:45 PM, Marko Milivojevic <[email protected]>wrote:

> > I know RD keeps 10.0.0./8 of customer A separate from 10.0.0./8 of
> customer
> > B.
>
> And this is good understanding. Now, for the final bit - that's the
> ONLY thing it does!
>
> > But if the final import export is done on the basis of RT, where RD is
> > actually being compared ?
>
> Nowhere. The only purpose of RD is to keep prefixes "unique", i.e.
> allow overlapping IPv4 address space by prepending them with RD.
>
> --
> Marko Milivojevic - CCIE #18427
> Senior Technical Instructor - IPexpert
>
> Mailto: [email protected]
> Telephone: +1.810.326.1444
> Fax: +1.810.454.0130
> Community: http://www.ipexpert.com/communities
>



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