More MTU questions

Pippin Wallace pwallace at
Fri Dec 14 19:14:35 CET 2018

WG List,

I have read the previous posts in the archive that mentioned MTU but did
not derive an answer to the following.

I had a frame length of 1474 try to transit WG and it sent back a ICMP
"fragmentation needed" but the source would not fragment the packet.  So I
upped the wg0 MTU to 1488, which worked for this frame, but saw all the
notes about the going over 1440 for IPv4 traffic may cause problems.

What is the best approach to deal with this problem?  I read about MSS
clamping but am not sure this will work or is the best first approach.

I am out of my depth with this at present and could really use some advice
from this expert group.

If I just need to read an RFC or other doc would you please point me in the
right direction?

Sincere regards,


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