[c-nsp] Good practices for peering

[Danny McPherson]

On Jan 2, 2006, at 5:52 PM, Richard J. Sears wrote:

> Thanks Arnold -
>
> I assume that if I already have those routes in my IGP via some  
> other way
> that I can safely disregard the set-next-hop-self...?

See my earlier response for some additional insight (our messages
likely passed on the wire :-).

However, in short recall that the motivations are quite different when
applying this to iBGP peers (which Arnold mentions) versus eBGP
peers, both of which I recommend.   A quick summary:

EBGP next-hop-self configuration:

  o static setting
  o ensure NBMA connectivity

IBGP next-hop-self configuration:

  o update packing
  o remove external subnets from IGP (lots of benefits)
  o TE, etc..
  o NBMA depending on where next hop is derived

There are some tweaks and caveats that need to be considered with
things like route reflection (next-hop-self doesn't apply to reflected
routes as a default behavior) and confederations, etc..  And I'm pretty
sure there are other reasons for both of these, just  haven't put a  
whole
lot of thought into it at the moment :-)

-danny