[SOLVED] Network disconnects after reboot. Works after switching ethernet ports manually.

[dopamine808]

Hey,

I have a proxmox server with 2 ethernet ports. I have just one connected to the modem which is bridged to my VMs. This setup worked initially but I recently had to reinstall proxmox due to a boot USB failure and I'm now having this issue:

After every reboot my server is no longer reachable. I can only fix it by switching the port the ethernet is plugged into manually.

On my modem the server is showing up as 2 different devices with the same IP address and I assume it switches every time I reboot and switch ethernet ports.

Here is my current /etc/network/interfaces:

auto lo
iface lo inet loopback

iface rename2 inet manual

iface eno1 inet manual

auto vmbr0
iface vmbr0 inet static
        address 192.168.1.42
        netmask 255.255.255.0
        gateway 192.168.1.1
        bridge-ports eno1
        bridge-stp off
        bridge-fd 0

This is result of ip addr:

root@proxmox:~# ip addr
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
valid_lft forever preferred_lft forever
2: eno1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq master vmbr0 state UP group default qlen 1000
link/ether 0c:9d:92:c4:ce:dc brd ff:ff:ff:ff:ff:ff
3: rename3: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
link/ether 0c:9d:92:c4:ce:dd brd ff:ff:ff:ff:ff:ff
4: vmbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether 0c:9d:92:c4:ce:dc brd ff:ff:ff:ff:ff:ff
inet 192.168.1.42/24 brd 192.168.1.255 scope global vmbr0
valid_lft forever preferred_lft forever
inet6 2605:a601:5592:1a00:e9d:92ff:fec4:cedc/64 scope global dynamic mngtmpaddr
valid_lft 3598sec preferred_lft 3598sec
inet6 fe80::e9d:92ff:fec4:cedc/64 scope link
valid_lft forever preferred_lft forever
5: br-a47800fd9a2c: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default
link/ether 02:42:05:5d:0f:f0 brd ff:ff:ff:ff:ff:ff
inet 172.19.0.1/16 brd 172.19.255.255 scope global br-a47800fd9a2c
valid_lft forever preferred_lft forever
inet6 fe80::42:5ff:fe5d:ff0/64 scope link
valid_lft forever preferred_lft forever
6: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default
link/ether 02:42:eb:1a:57:2f brd ff:ff:ff:ff:ff:ff
inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
valid_lft forever preferred_lft forever
8: veth7cb0714@if7: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-a47800fd9a2c state UP group defau
lt
link/ether 62:2b:7d:18:55:2e brd ff:ff:ff:ff:ff:ff link-netnsid 0
inet6 fe80::602b:7dff:fe18:552e/64 scope link
valid_lft forever preferred_lft forever

I've tried switching between rename2 and rename3 but when I reboot, switch ethernet ports, and run ip addr again its renamed to the other number.


Here's ifconfig -a:

root@proxmox:~# ifconfig -a
br-a47800fd9a2c: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 172.19.0.1 netmask 255.255.0.0 broadcast 172.19.255.255
inet6 fe80::42:5ff:fe5d:ff0 prefixlen 64 scopeid 0x20<link>
ether 02:42:05:5d:0f:f0 txqueuelen 0 (Ethernet)
RX packets 411 bytes 81230 (79.3 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 432 bytes 29353 (28.6 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

docker0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 172.17.0.1 netmask 255.255.0.0 broadcast 172.17.255.255
ether 02:42:eb:1a:57:2f txqueuelen 0 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

eno1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
ether 0c:9d:92:c4:ce:dc txqueuelen 1000 (Ethernet)
RX packets 4993 bytes 1142445 (1.0 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 1243 bytes 822225 (802.9 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device memory 0xdfd00000-dfd7ffff

lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 2737 bytes 206740 (201.8 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 2737 bytes 206740 (201.8 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

rename3: flags=4098<BROADCAST,MULTICAST> mtu 1500
ether 0c:9d:92:c4:ce:dd txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device memory 0xdfc00000-dfc7ffff

veth7cb0714: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::602b:7dff:fe18:552e prefixlen 64 scopeid 0x20<link>
ether 62:2b:7d:18:55:2e txqueuelen 0 (Ethernet)
RX packets 411 bytes 86984 (84.9 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 445 bytes 30359 (29.6 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

vmbr0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.42 netmask 255.255.255.0 broadcast 192.168.1.255
inet6 fe80::e9d:92ff:fec4:cedc prefixlen 64 scopeid 0x20<link>
inet6 2605:a601:5592:1a00:e9d:92ff:fec4:cedc prefixlen 64 scopeid 0x0<global>
ether 0c:9d:92:c4:ce:dc txqueuelen 1000 (Ethernet)
RX packets 4762 bytes 984627 (961.5 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 873 bytes 797817 (779.1 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

I'm fairly sure docker0 & veth7cb0714 are unrelated as they are new (probably used for the scrutiny docker container) and didn't exist when I first started having this issue.

This is what it looks like on web GUI:


Please let me know if I can provide any more info.

Any help would be very much appreciated.

 

[Alwin]

Can you please add how you resolved it? Others will profit from your experience.