Can't connect to the network after NIC change

[FiltroMan]

Hi everyone,

I've been doodling around with Proxmox for a couple of months and, sadly, I've recently lost the onboard Ethernet port on the PC I'm using as a server, the same I used for the initial configuration. I have handy a USB to Ethernet adapter which is being detected via lsusb but I cannot get the server to show up on the network.

I tried:

• Disabling the integrated NIC
• Plugged the adapter in different USB ports (bar one, works on every single one of them)
• Using the ip addr command I found the NIC name and updated the /etc/network/interfaces

So far, there is no way for me to get the damn thing back up and running again: I must be clearly missing something, can you help me out?

Many thanks in advance

 

[Moayad]

Hello,

Please post the output of the below commands:

ip a
cat /etc/network/interfaces

 

[FiltroMan]

Hello,

Please post the output of the below commands:

ip a
cat /etc/network/interfaces

Thanks for your prompt reply, here's the output for both commands:

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 valid_lft forever preferred_lft forever 2: enx3c18a01d4b85: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master vmbr0 state UP group default qlen 1000 link/ether 3c:18:a0:1d:4b:85 brd ff:ff:ff:ff:ff:ff 3: vmbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether 3c:18:a0:1d:4b:85 brd ff:ff:ff:ff:ff:ff inet 192.168.1.100/24 scope global vmbr0 valid_lft forever preferred_lft forever inet6 fe80::3e18:a0ff:fe1d:4b85/64 scope link valid_lft forever preferred_lft forever 4: tailscale0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1280 qdisc pfifo_fast state UNKNOWN group default qlen 500 link/none inet6 fe80::4cf0:3541:9306:c613/64 scope link stable-privacy valid_lft forever preferred_lft forever 5: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default link/ether 02:42:d9:38:86:c9 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 6: veth105i0@if2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master vmbr0 state UP group default qlen 1000 link/ether fe:9c:1f:27:fb:a8 brd ff:ff:ff:ff:ff:ff link-netnsid 0 7: veth100i0@if2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master fwbr100i0 state UP group default qlen 1000 link/ether fe:b8:9d:54:9e:88 brd ff:ff:ff:ff:ff:ff link-netnsid 1 8: fwbr100i0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether 32:e1:e9:34:cb:c6 brd ff:ff:ff:ff:ff:ff 9: fwpr100p0@fwln100i0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master vmbr0 state UP group default qlen 1000 link/ether ca:ad:8d:85:bb:4f brd ff:ff:ff:ff:ff:ff 10: fwln100i0@fwpr100p0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master fwbr100i0 state UP group default qlen 1000 link/ether 7e:50:ed:f3:94:89 brd ff:ff:ff:ff:ff:ff 11: tap102i0: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master fwbr102i0 state UNKNOWN group default qlen 1000 link/ether 9e:c9:1e:a1:e3:5e brd ff:ff:ff:ff:ff:ff 12: fwbr102i0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether 56:78:7a:a3:49:0e brd ff:ff:ff:ff:ff:ff 13: fwpr102p0@fwln102i0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master vmbr0 state UP group default qlen 1000 link/ether 26:c1:c7:00:99:31 brd ff:ff:ff:ff:ff:ff 14: fwln102i0@fwpr102p0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master fwbr102i0 state UP group default qlen 1000 link/ether 86:95:6b:44:30:cb brd ff:ff:ff:ff:ff:ff 15: veth103i0@if2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master fwbr103i0 state UP group default qlen 1000 link/ether fe:d7:da:b0:09:11 brd ff:ff:ff:ff:ff:ff link-netnsid 2 16: fwbr103i0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether a6:d1:78:fc:60:74 brd ff:ff:ff:ff:ff:ff 17: fwpr103p0@fwln103i0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master vmbr0 state UP group default qlen 1000 link/ether 92:5a:63:47:81:d4 brd ff:ff:ff:ff:ff:ff 18: fwln103i0@fwpr103p0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master fwbr103i0 state UP group default qlen 1000 link/ether 22:a3:34:9d:7f:d1 brd ff:ff:ff:ff:ff:ff

cat /etc/network/interfaces # network interface settings; autogenerated # Please do NOT modify this file directly, unless you know what # you're doing. # # If you want to manage parts of the network configuration manually, # please utilize the 'source' or 'source-directory' directives to do # so. # PVE will preserve these directives, but will NOT read its network # configuration from sourced files, so do not attempt to move any of # the PVE managed interfaces into external files! auto lo iface lo inet loopback auto enx3c18a01d4b85 iface enx3c18a01d4b85 inet manual auto vmbr0 iface vmbr0 inet manual address 192.168.1.100/24 gateway 192.168.1.1 bridge-ports enx3c18a01d4b85 bridge-stp off bridge-fd 0 iface wlp2s0 inet manual

 

[Moayad]

Hi,

The bridge vmbr0 should be as the below:

auto vmbr0
iface vmbr0 inet static
    address 192.168.1.100/24
    gateway 192.168.1.1
    bridge-ports enx3c18a01d4b85
    bridge-stp off
    bridge-fd 0

i.e static instead of manual. Please edit the network configuration file and do ifreload -a command.

 

[FiltroMan]

Hi,

The bridge vmbr0 should be as the below:

auto vmbr0
iface vmbr0 inet static
    address 192.168.1.100/24
    gateway 192.168.1.1
    bridge-ports enx3c18a01d4b85
    bridge-stp off
    bridge-fd 0

i.e static instead of manual. Please edit the network configuration file and do ifreload -a command.

I can't remember where I found that info (I'd guess from another thread on here), but someone with a somewhat similar issue solved by switching the manual to static variable. I'll try once I'll be back, heading for vacation, thanks for the tip though

 

[FiltroMan]

Hi,

The bridge vmbr0 should be as the below:

auto vmbr0
iface vmbr0 inet static
    address 192.168.1.100/24
    gateway 192.168.1.1
    bridge-ports enx3c18a01d4b85
    bridge-stp off
    bridge-fd 0

i.e static instead of manual. Please edit the network configuration file and do ifreload -a command.

Hi,

I just tried as you suggested and still can't get the server to connect

 

[Moayad]

Hi,

Does the ifreload -a command say anything?

 

[Neobin]

Maybe your 5: docker0 and/or 4: tailscale0 directly installed on the PVE-host strikes back now?

 

[FiltroMan]

Hi everyone,

I moved the server to another location (closer to the main router) and it works flawlessly, I guess something in the in wall cabling went awry and brought down the interface with it. The USB dongle works brilliantly with every single container and VM on my server accessible again, nothing wrong with the configuration, though the "static" setting fixed the issue.

Thanks everyone for helping me out, the thread can be closed