[c-nsp] IOS XR / advertise best-external

[Dan Peachey]

On 18 May 2015 9:40 pm, "Gert Doering" <gert at greenie.muc.de> wrote:
>
> Hi,
>
> On Mon, May 18, 2015 at 09:23:50PM +0100, Dan Peachey wrote:
> > If that's the case I find it strange why that's now the default
behaviour.
> > Surely that's the point of 'additional-paths' to control what routes you
> > want to have backups for. In my case I definitely wouldn't have wanted
> > backup routes for everything by default.
>
> BGP add-path is for sending multiple routes for a single prefix towards a
> BGP peer.  Different thing again...
>
> gert

You can use 'additional-paths selection' on its own without 'send' or
'receive' to filter what backup routes you install in the RIB/FIB. Using
this on its own does not negotiate add-path with any peers or advertise
multiple routes.

Unless I missed the point, the default behaviour of enabling
'best-external' now seems to be to install the backup route in the RIB/FIB,
which was not the case last time I looked at it and may not be desired
behaviour.

Regards,

Dan

Regards,

Dan