BGP route back

Roman Romanyak roman.romanyak at
Tue Jan 22 19:52:37 CET 2019

Thank you for the advise, Ondrej. I've heard that some l3 switches do not
support add-path feature in VRFs, but in this case I'm using routers, so
this should work fine.


On Tue, Jan 22, 2019 at 9:38 AM Ondrej Zajicek <santiago at>

> On Fri, Jan 18, 2019 at 01:14:47PM -0500, Roman Romanyak wrote:
> > Hello Bird users,
> >
> > Does anyone know if there is a way to announce a BGP route back to the
> > router it was received from.
> > I need to do this for the following scenario.
> Hi
> I recently thought about a setup where a route-reflector modifies routes
> and propagates modified routes to its clients. To avoid issue with
> announcing route back and with (like you noticed) and with withdrawing
> original route (like Alexander Zubkov noticed) there is a simple solution:
> Use two RIB routing tables on clients and two single-directional BGP
> sessions - first RIB table collects routes from EBGP peers and uses first
> BGP session to propagate that to route-reflector, then second BGP session
> is used to propagate all routes back from route-reflector to second table
> in clients, while second table is connected to kernel/FIB.
> Such setup could be done in BIRD, i am just wondering whether client part
> of such setup could be done with common L3 switches with BGP support.
> --
> Elen sila lumenn' omentielvo
> Ondrej 'Santiago' Zajicek (email: santiago at
> OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3,
> "To err is human -- to blame it on a computer is even more so."
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the Bird-users mailing list