[Babel-users] MTU based routing for tunnel based babel networks?

[Juliusz Chroboczek]

>> RFC 2460: "link MTU - the maximum transmission unit, i.e., maximum packet
>>            size in octets, that can be conveyed over a link."

> I read this as "link MTU" being the maximum packet size that you could ever
> hope to be able send but the link technology could very well not allow the
> maximum at times.

Daniel, the specs are perfectly clear: there is no licence given to nodes
to systematically drop packets smaller than MTU.  In fact, such links
break TCP, as you've discovered.

> I'm still not sold on your argument, but it hardly matters. Tunnels on top
> of the internet exist so we kind of just have to deal with it.

Nobody is denying that.  Please see RFC 4459, which describes how to make
them work reasonably well.

-- Juliusz