[147084] in North American Network Operators' Group
Re: Link local for P-t-P links? (Was: IPv6 prefixes longer then /64:
daemon@ATHENA.MIT.EDU (Tom Lanyon)
Thu Dec 1 19:27:53 2011
From: Tom Lanyon <tom+nanog@oneshoeco.com>
In-Reply-To: <CAAAas8Hu5HLVjf+Xx9edF_J_fTm8JmSFnGsSQJVb405y3htr=Q@mail.gmail.com>
Date: Fri, 2 Dec 2011 10:56:43 +1030
To: Mike Jones <mike@mikejones.in>,
Ray Soucy <rps@maine.edu>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Hi,
On 01/12/2011, at 12:45 PM, Mike Jones wrote:
> Link-Local?
> [snip]
> Am I a complete idiot missing some obvious major issues with link
> locals, or am i just the only one not thinking IPv4-think? Opinions?
> :)
In a DC / hosting provider context, we're doing this.
We started out assigning all of our PtP links (where we had /31s in the =
IPv4 world) IPv6 /64s and addressing using ::1 and ::2 with /127 masks =
from these /64s (to address potential ND table overflow concerns), but =
have now settled on using automatic link-local addresses instead.
Our IGP propagates the routers' /128 loopbacks and these are used for =
routing user traffic.
Having the IGP table only contain the /128 loopbacks, and none of the =
PtP networks is nice. :)
On 01/12/2011, at 12:52 PM, Ray Soucy wrote:
> I for one get really irritated when my traceroutes and pings are
> broken and I need to troubleshoot things. ;-) But I guess something
> has to give.
You don't have to give up working traceroute / ping to use link-local on =
your PtPs. =20
Our traffic routes through globally reachable router loopbacks which =
looks pretty in traceroutes, are pingable and doesn't break PMTUD.
Tom
