[j-nsp] Optimizing the FIB on MX

[Olivier Benghozi]

I think that this recommandation makes sense: I don't see any good reason to have, by default, eBGP routes with a better administrative distance ("preference", in Junos) than your IGP (OSPF or ISIS).

This been said, in all BGP implementations, the BGP best path selection algo includes a [prefer eBGP routes] item, whatever the admin-distance value is set when BGP pushes its routes to the RIB.
Both things are different.

So eBGP _is_ preferred over iBGP (at a certain point in the selection algo). According to the protocol definition, in fact (RFC 4271 page 81).


> 18 feb 2016 at 12:12, sthaug at nethelp.no wrote :
> 
>> *not sure what was Juniper and ALU thinking when they came up with the same protocol preference for eBGP and iBGP routes, there's a ton of reasons why you always want to prefer closest AS-EXIT.
> 
> Probably the same as Cisco, when Cisco on multiple occasions have
> promoted using the same administrative distance (200) for both EBGP
> and IBGP as "best practice".