You filed the bug report against NetworkManager. But the "up.d" hook is called differently in NM, see https://netplan.io/faq#use-pre-up-post-up- etc-hook-scripts
If this is about /etc/network/if-up.d then it should be targeted towards the "ifupdown" package. I'm adding a corresponding bug task. ** Also affects: ifupdown (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to network-manager in Ubuntu. https://bugs.launchpad.net/bugs/2064093 Title: if-up.d files do not have effect on ubuntu 24.04 LTS Status in ifupdown package in Ubuntu: New Status in network-manager package in Ubuntu: New Bug description: Some time ago I wrote a detailed answer to fix an error for lowering MTU size for a cisco-compatible VPN (here:https://unix.stackexchange.com/questions/768757/unable-to-ssh- into-remote-machine-but-able-to-ping-vpnc/768758#768758) After upgrading to Ubuntu 24.04 LTS, I'm unable with the same steps to lower the MTU size. In particular, if I run the following command from the terminal sudo ifconfig your_tunnel_name mtu 1370 up it seems to lower the MTU size. However, the script under /etc/network/if-up.d is not automatically triggered. Does something change with the newer Ubuntu version? To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ifupdown/+bug/2064093/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp