Change MTU on Proxmox backup server
Edit the /etc/network/interfaces file. Add mtu 9000 to the interface. iface lo inet loopback auto enp4s0 iface enp4s0 inet static address 172.22.36.146/20 gateway 172.22.47.254 mtu 9000 iface enp5s0 inet manual Restart the interface root@hpvebkpdev01:~# systemctl restart networking.service root@pvebkpdev01:~# systemctl status networking.service ? networking.service - Network initialization Loaded: loaded (/lib/systemd/system/networking.service; enabled; vendor preset: enabled) Active: active (exited) since Sun 2022-02-13 13:03:11 CST; 14s ago Docs: man:interfaces(5) man:ifup(8) man:ifdown(8) Process: 2052 ExecStart=/usr/share/ifupdown2/sbin/start-networking start (code=exited, status=0/SUCCESS) Main PID: 2052 (code=exited, status=0/SUCCESS) CPU: 476ms Feb 13 13:03:10 pvebkpdev01 systemd[1]: Starting Network initialization....