LXC client gets no network after client reboot

[hagen]

At PVE 8.3.1 I have a LXC client with Ubuntu JAMMY. After a release upgrade to NOBLE, the IPv4 address is gone:

root@hf-s01:~# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host noprefixroute
       valid_lft forever preferred_lft forever
2: eth0@if117: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether XX:XX:XX:XX:XX:XX brd ff:ff:ff:ff:ff:ff link-netnsid 0

I only get the network online again, if I completely remove the network of the container in PVE and recreate it.

root@hf-s01:~# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host noprefixroute
       valid_lft forever preferred_lft forever
112: eth0@if113: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether XX:XX:XX:XX:XX:XX brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 192.168.77.1/24 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fd0c:2c8e:53da:0:b061:bff:fe75:29e2/64 scope global dynamic mngtmpaddr
       valid_lft 7018sec preferred_lft 3418sec
    inet6 2001:9e8:3da4:2700:b061:bff:fe75:29e2/64 scope global dynamic mngtmpaddr
       valid_lft 7018sec preferred_lft 3418sec
    inet6 fe80::b061:bff:fe75:29e2/64 scope link
       valid_lft forever preferred_lft forever

When I reboot the LXC container, the IPv4 is gone again.

The network service is up and running:

root@hf-s01:~# systemctl status networking
● networking.service - Raise network interfaces
     Loaded: loaded (/usr/lib/systemd/system/networking.service; enabled; preset: enabled)
     Active: active (exited) since Sat 2024-12-21 09:20:07 UTC; 1s ago
       Docs: man:interfaces(5)
    Process: 260 ExecStart=/sbin/ifup -a --read-environment (code=exited, status=0/SUCCESS)
    Process: 315 ExecStart=/bin/sh -c if [ -f /run/network/restart-hotplug ]; then /sbin/ifup -a --read-environment --allow=hotplug; fi (code=exited, status=0/SUCCESS)
   Main PID: 315 (code=exited, status=0/SUCCESS)
        CPU: 33ms

The network service is configured by PVE:

root@hf-s01:~# cat /etc/systemd/network/eth0.network
[Match]
Name = eth0

[Network]
Description = Interface eth0 autoconfigured by PVE
Address = 192.168.77.1/24
Gateway = 192.168.77.253
DHCP = no
IPv6AcceptRA = false

The IPv4 routes are also gone:

root@hf-s01:~# ip r

 

[UdoB]

Compare the NIC names in the output of ip link show.

 

[hagen]

root@hf-s01:~# ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0@if124: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
    link/ether XX:XX:XX:XX:XX:XX brd ff:ff:ff:ff:ff:ff link-netnsid 0