Hi Joe, > -----Original Message----- > From: Joe Touch [mailto:[email protected]] > Sent: Thursday, April 23, 2015 12:48 PM > To: Templin, Fred L; Ronald Bonica; [email protected] > Subject: Re: [Int-area] I-D Action: draft-ietf-intarea-gre-ipv6-07.txt > > > > On 4/23/2015 12:29 PM, Templin, Fred L wrote: > ... > >>> You had better be able to trust that the source > >>> of the PTB is trustworthy and not sending bogus PTBs. > >> > >> That's always been true. > > > > Only in tightly-controlled operational environments, where there are > > no bad routers on the path, no ICMP PTB blockages, and no opportunity > > for an attacker to inject a spurious PTB. And also, only when the path > > from the tunnel ingress to the original source is equally well behaved > > (otherwise, the original source would see a black hole). > > Bad routers can always send bad PTBs, and PTBs can be (and have been) > blocked. > > None of that is new, and it can impact all packet sources including > tunnels and real endpoints.
But, good PTBs are useful when you can get them. > That's also why the mechanism we discussed does NOT rely on PTBs - it > relies on liveness detection. Unless you want the egress to ACK each data packet received, I don't see how that squares with ECMP/LAG. If your liveness detection is only checking some paths and not others, data packets may be black holing over other (untested) paths. Thanks - Fred [email protected] > Joe _______________________________________________ Int-area mailing list [email protected] https://www.ietf.org/mailman/listinfo/int-area
