Hi, Fred, > On Dec 8, 2021, at 11:52 AM, Templin (US), Fred L <fred.l.temp...@boeing.com> > wrote: > > Joe, RFC3819, Section 2 in particular gives BCPs for setting link MTUs.
NATs and tunnels don’t have control over the link MTUs over which they operate; the user doesn’t have control over how those are composed or interact. > By my read, the > only links that would set an MTU smaller than 576 should therefore only occur > at the > network edges; not somewhere in the middle of the network. Tunnels create an tunnel MTU (which is the link MTU, thinking of the tunnel as a link) by fragmenting at the ingress and reassembling at the egress. That happens anywhere in the network. While it PRESENTS an effective MTU of the tunnel as a link, it doesn’t operate as if it avoids fragmentation. Joe _______________________________________________ Int-area mailing list Int-area@ietf.org https://www.ietf.org/mailman/listinfo/int-area
