Hi Mikael, > -----Original Message----- > From: Mikael Abrahamsson [mailto:[email protected]] > Sent: Friday, January 17, 2014 8:15 AM > To: Templin, Fred L > Cc: Mark Townsley; [email protected] > Subject: RE: MTU handling in 6RD deployments > > On Fri, 17 Jan 2014, Templin, Fred L wrote: > > > Sorry, I was looking at the wrong section. I see now that Section 8 is > > talking about a method for a CE to send an ordinary data packet that > > loops back via the BR. That method is fine, but it is no more immune to > > someone abusing the mechanism than would be sending a ping (or some > > other NUD message). By using a ping, the BR can impose rate-limiting on > > its ping responses whereas with a looped-back data packet the BR really > > can't do rate limiting. > > You don't ping the BR, you ping yourself via the BR. The BR only forwards > the packet. > > > Also, Section 8 of RFC5969 only talks about the CE testing the forward > > path to the BR. Unless the BR also tests the reverse path to the CE it > > has no way of knowing whether the CE can accept large packets. > > You misread the text.
I don't see anywhere where it says that the BR should also ping the CE and cache a boolean "ACCEPTS_BIG_PACKETS" for this CE. If the BR doesn't do that, it needs to set its MTU to the CE to 1480 (or 1472 or something). Thanks - Fred [email protected] > -- > Mikael Abrahamsson email: [email protected]
