Thanks for keeping us on our toes Fred!I'd like to clarify of course that some of the MTU issues we discussed were not specific to tunneling, but to mismatched MTUs on a home LAN vs. WAN interface in general. The extra 20 bytes of a 6rd or 6to4 encapsulation isn't significant when trying to solve support of 9K jumbo frames and standard 1500 byte ethernet MTUs in the same network.
Tunneling does affect MTU, no doubt. I'll point out that with 6rd, the deployment space of the tunnel is limited, making it dramatically easier to "tune" than with 6to4. Unlike SEAL, this is still essentially an operator tweaked value in the current deployment model.
- Mark Templin, Fred L wrote:
Hi, Tunnel MTU issues came up in both the 6rd and CPE router discussions today. As near as I can tell, the issues are not going to go away and will keep coming up over and over again the more we talk about tunneling. SEAL is proposal that has a real chance of cleaning up the issues once and for all. I will be briefing the updates to the document at the intarea meeting tomorrow, but in the meantime the draft is here: http://tools.ietf.org/html/draft-templin-intarea-seal-05 Comments or questions welcome, Fred fred.l.templin@boeing.com