[c-nsp] ME3600 iBGP to RR

[Mark Tinka]

On 7/Mar/15 15:50, Nick Hilliard wrote:
> On 07/03/2015 05:25, Mark Tinka wrote:
>> My BGP-SD route-map includes communities and other necessary match
>> conditions that identify prefixes I'd like to download into FIB.
> but you can only use table-map with a deny-all route-map if the PE is a
> pure edge device, i.e. if all traffic is either local or north-south and
> you can get away with just a default route and connected/static routes.

I agree that if it's an edge device with a stub or direct upstream,
e.g., a CPE device connected to an upstream ISP, then this makes sense.

But an edge device in an PoP used to terminate customers makes a
north-south topology interesting because if the ISP distributes routing
with no other router in the PoP acting as a default gateway, you end up
with the problem of which other router to use as your default gateway.
If you operate a BGP-aware core, then pointing default or specifics to
the core router in the PoP is an option (you still trombone traffic
destined for other non-core routers within the PoP, however...). But if
you operate a BGP-free core, then it becomes interesting which box you
choose to point default or specifics to on the back of a "deny-all"
BGP-SD route-map.

We deploy some ME3600X's within a PoP as edge routers for customers, but
these do not require any global BGP routes anyway. So use of BGP-SD in
this case is redundant.

> East-west traffic necessarily depends on visibility into the rest of the
> network, which increases the risk of booboos.

Yes, this is where we deploy BGP-SD, as unlike the ME3600X's deployed in
the case mentioned above, these require global BGP routes.

Mark.