Sending only default route to downstream users?

[Mike Jones]

On 24 March 2017 at 13:37, Michael McConnell <michael at winkstreaming.com> wrote:
>
> Hello all,
>
> I receive a full iBGP table from my uplinks, however I want to just pass a default route / partial table to my downstream clients.
>
> I’ve tried various options such as gateway direct and multihop, try to turn it into a eBGP situation with no luck.
>
> Can anyone point me in the right direction?
>
> Thank you very much for your time and help,
> Mike
>

Hi,

You are looking for filters. These define rules that get checked
against every route imported/exported and can either accept/reject a
route or can even modify attributes. Filters can be applied on export
to control what you advertise, and on import to control what you
accept.

I would normally leave you to figure out the details by yourself,
however the documentation isn't exactly the best at telling you how to
do these simple tasks so it would probably save a bit of time if I
gave you an example.

filter senddefault {
        if net = 0.0.0.0/0 then accept;
        reject;
};

and the v6 version would be

filter senddefault {
        if net = ::0/0 then accept;
        reject;
};

- Mike Jones