[c-nsp] ME3600 iBGP to RR

[Nick Hilliard]

On 06/03/2015 05:35, Mark Tinka wrote:
>> > You just need to make sure you never mess up the route-map used for SD.
> If you want to be simple, a simple "route-map BLAH deny 10" is all you
> need to have nothing installed in the FIB.

This will cause traffic to go north-south on your network in situations
where it might be more efficiently handled as east-west.  Depending on the
network structure, this might not be a problem, e.g. if the me3600 is a
strict PE / distribution device.  If there are any east-west connections,
deny-all on bgp won't work well.  Obviously this assumes that ibgp is being
used as igp, with isis/ospf as strict topology engine only.  If you're
using a link state protocol for connected / static prefix distribution
(urgh), east-west traffic will stay that way.  But then we wouldn't be
having this conversation.

Otherwise, Adam is correct to say that using selective download shifts the
problem space from one route-map to another.  Ultimately you still need to
be careful.  Dropping a spanner into the cogs nearly always causes damage,
no matter what the situation.

Nick