# IP MTU seems to be 1450:
root@arturo-test-vm4:~# ping -c 1 -M do -s 1423 172.16.129.237
PING 172.16.129.237 (172.16.129.237) 1423(1451) bytes of data.
ping: local error: message too long, mtu=1450
# Leaving a max ping data size of 1422 (1450 - (10 UDP + 8 ICMP))
root@arturo-test-vm4:~# ping -c 1 -M do -s 1422 172.16.129.237
PING 172.16.129.237 (172.16.129.237) 1422(1450) bytes of data.
1430 bytes from 172.16.129.237: icmp_seq=1 ttl=64 time=4.09 ms
## 1500 works though if we allow it fragment
root@arturo-test-vm4:~# ping -c 1 -s 1500 172.16.129.237
PING 172.16.129.237 (172.16.129.237) 1500(1528) bytes of data.
1508 bytes from 172.16.129.237: icmp_seq=1 ttl=64 time=3.10 ms
## MTU is actually hard set on the interface, this isn't coming from pmtud
root@arturo-test-vm4:~# ip --json link show dev ens3 | jq | grep mtu
"mtu": 1450,