[c-nsp] 6PE our only option?

Lobo lobotiger at gmail.com
Thu Mar 29 20:25:17 EDT 2012


Apologies if this is a little long but looking for some friendly advice 
from you experts on rolling out IPv6 on our network.

Our network follows a traditional model where it's 
edge----distribution----core-----gwy for our internet customers.  The 
entire distribution, core and gwy routers have had MPLS enabled on them 
for a couple of years in order to offer EoMPLS like services.  The edge 
routers have not had MPLS enabled on them as there was no real need 
since they only provide internet access.  The IGP is OSPF and BGP is 
running on the distribution & gwy routers towards our route-reflectors.  
The core is BGP less now so they are functioning as true P routers.

We have managed to dual stack (v4 & v6) all of our distribution, core 
and gwy routers' interfaces as we believed that dual stack is always the 
preferred option.  We followed the same principles as our v4 
implementation (loopbacks & PTPs only in the IGP and static/connected 
routes at the edge distributed via iBGP).  Upon installing a new edge 
router that would participate in IPv6 we discovered that the core could 
not route the packets to other IPv6 destinations because it only knows 
about LBs & PTPs.  Even if it made it to the gwy because of a default 
route (::/0), there were times when another gwy router had a better 
route and then we would have packets bouncing back and forth between a 
gwy and core router until the TTL expired.

Now we're at the point of wondering if 6PE is our only option in order 
to forward the packets or if we go back to the old way of doing things 
by re-enabling BGP on the core (for ipv6 only) and having a partial set 
of ipv6 routes?  Personally I've been configuring 6PE in our lab for the 
entire week and it's really racking my head.  There are times when I 
have things working and then I make the smallest change in a route-map 
and suddenly things no longer work.  Do I configure the 6PE stuff on the 
edge router or can it start at the distribution router?  Traceroutes 
look really odd with the core not showing and I'm wondering if I'm 
introducing more problems for our NOC to troubleshoot (and learn) vs 
going with some other, simpler option.

Right now I'm really wishing that LDPv6 was implemented.  :)

Appreciate any comments, feedback or suggestions.  Please let me know I 
can provide any further information.

Thanks!

Jose



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