Host not reachable after reboot (first after fresh install)

[2Stoned]

Hi there

Yesterday, I installed proxmox following this tutorial, from which I deviated slightly by using one SSD for the host + isos and created a ZFS mirror with two NVMe SSDs for the VMs. After that I set up a Windows10 VM. In the end, I shut down the server.
Today, I powered on the server, I get the usual welcome screen on the host ("Welcome to the Proxmox Virtual En....") where the IP I set yesterday is shown. But, my Router doesn't list the host under connected devices and the host is not reachable via browser under this IP.
Besides the onboard NIC, which I used to set it up, there is a dedicated NIC as well. For testing purposes I connected both now, without any one of the two getting an IP from the router (at least the router does not list any).
How can I reconnect the server? I have physical access to it, i.e. I can use the shell.

Thank you very much for your help.

 

[Moayad]

Hi,

Please post your network configuration cat /etc/network/interfaces and output of command ip a

 

[2Stoned]

Thank you very much for your kind reply.
My interfaces are the following:

auto lo
iface lo inet loopback

iface enp6s0 inet auto

auto vmbr0
iface vmbr0 inet static
    address 192.168.0.50
    netmask 255.255.255.0
    gateway 192.168.0.1
    bridge_ports enp6s0
    bridge_stp off
    bridge_fd 0

iface enp5s0 inet manual

ip a returns:

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: enp7s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether b4:22:99:aa:ee:dd brd ff:ff:ff:ff:ff:ff
3: enp5s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether a8:ee:44:66:aa:44 brd ff:ff:ff:ff:ff:ff
4: wlp6s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 94:ee:ff:aa:22:99 brd ff:ff:ff:ff:ff:ff

 

[Moayad]

Hi,

Probably you changed network card so to fix it,, You need to modify your network interfaces /etc/network/interfaces and just edit enp6s0 to enp7s0

I hope this helps

 

[2Stoned]

Works like a charm. Problem solved. Thank you very very much! Have a wonderful day!

 

[2Stoned]

The solution works - but: After every other reboot it changes from enp7s0 to enp6s0 just to change from enp6s0 back to enp7s0 after two reboots. Why is it alternating between the two all the time? Can I make it stick?

 

[Moayad]

Hi,

Why is it alternating between the two all the time?

Read this!
https://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/

Can I make it stick?

Yes, just put GRUB_CMDLINE_LINUX_DEFAULT="net.ifnames=0 biosdevname=0" in /etc/default/grub then update-grub and reboot

 

[2Stoned]

Thank you very much. It looks good so far. Thank you also for the link to better understand the why! Very helpful, indeed!

 

[2Stoned]

Ok, ip a now always shows that the link is UP, but I can connect to the host only every second boot.

 

[Moayad]

Could you try to edit your config network from to auto manual like our wiki [0]


iface enp6s0 inet auto
to
iface enp6s0 inet manual

[0] https://pve.proxmox.com/wiki/Network_Configuration#_default_configuration_using_a_bridge

 

[2Stoned]

Sorry, I did not mention that I already did that before. My config looks like this atm:

auto lo
iface lo inet loopback

iface eth0 inet manual

auto vmbr0
iface vmbr0 inet static
        address 192.168.0.50
        netmask 255.255.255.0
        gateway 192.168.0.1
        bridge_ports eth0
        bridge_stp off
        bridge_fd 0

iface enp5s0 inet manual

 

[2Stoned]

I set up an Ubuntu VM with passed-through GPU, mouse, and keyboard. When the host is not reachable, also the VM cannot establish a network connection, even though ip a shows eth0 UP.
After a reboot, it is working fine again.