>> IP does not support variable MTU links. > > Excuse me, but that's plain false. IP was designed in an environment where > (non-ethernet) networks with various MTU standards were commonplace
Sorry, I wasn't clear. IP requires every link to have a well-defined MTU: all the nodes connected to a link must agree on the link's MTU. Now, I agree that it is possible to simulate a variable-MTU link, as describes in RFC 4459 Section 3.2, and it will mostly work. But that's not what IP was designed for, and I don't know whether it's possible to make it reliable. > There is a way: My routing protocol just has to stop picking links that are > obviously going to cause a problem. Could you please describe the problem in detail? Because I'm probably missing something. If Wireguard implements RFC 4459 Section 3.2, then pushing a too large packet over the tunnel, then Wireguard should synthesise an ICMP "packet too large", which will cause the sender to retry with a smaller packet. Is that not the case? I'm not opposed to your probing idea, but I'd really prefer to fully understand the problem first. -- Juliusz _______________________________________________ Babel-users mailing list [email protected] https://alioth-lists.debian.net/cgi-bin/mailman/listinfo/babel-users
