Mixed MTU hosts on a network

Jason A. Donenfeld Jason at zx2c4.com
Sat Apr 14 16:45:32 CEST 2018

Hi Roman,

That's strange; I'm unable to reproduce what you've described:

[+] NS1: ip link set wg0 mtu 1412
[+] NS2: ip link set wg0 mtu 1412
[+] NS1: wg set wg0 peer QXloTaPOwUTzqFElVLSD0vBc4sxjyoKtPBSaTkZHokY=
[+] NS2: wg set wg0 peer X0p7+UWc4wjaAmT73xAEuXLY80I6Gv8vTg6KwFHCPGs=
[+] NS0: iptables -A INPUT -m length --length 1473 -j DROP
[+] NS2: ping -c 1 -W 1 -s 1384
PING ( 1384(1412) bytes of data.
1392 bytes from icmp_seq=1 ttl=64 time=0.752 ms

--- ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.752/0.752/0.752/0.000 ms

In this case, WireGuard seems to be doing the right thing. Think you
could come up with some minimal test that exhibits the behavior you're


More information about the WireGuard mailing list