On Sun, Jun 06, 2021 at 01:14:16PM +0200, Peter Linder wrote: > This would break things for me. We're doing a lot of L2 over L3 site to > site stuff and we are using wireguard as the outer layer. Inner layer is > vxlan or l2tpv3. > > In particular, people connect lots of stuff with no regard for MTU. For > some things it's also very hard to change so we just assume people > don't. Since the L3 network typically has the same MTU as the inner L2 > network, we need fragmentation. There is no practical way to be able to > tell hosts on the L2 network about the limited mtu, for all we know they > don't even run IP....
I've not looked in to vxlan much, but for L2TP you always have recourse to RFC 4623, where the MRU & MRRU can be exchanged. DF