Proxmox Network issues - WebUi unreachable, if i add static, the VM and LXC's cannot reach the internet

R

rbhalla

Member
Mar 4, 2022
8
1
8
46
Hi All,
I have had proxmox running for a while without issues on a dell optiplex 7070. recently the server has started playing up.

I am running version 8.4.1.

My Config:
Code: 
auto lo
iface lo inet loopback

iface eno1 inet manual

auto vmbr0
iface vmbr0 inet static
    address 192.168.1.22/24
    gateway 192.168.1.1
    bridge-ports eno1
    bridge-stp off
    bridge-fd 0


this is my hosts file:
Code: 
127.0.0.1 localhost.localdomain localhost
192.168.1.22 proxmox.test.network proxmox

# The following lines are desirable for IPv6 capable hosts

::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts

when i do an ping 8.8.8.8 i get:
Network in Unreachable

when i do ip addr, i have:
1: lo
2: eno1
3: tailscale0
4: vmbr0
followed by vethxxxx

ip route shows nothing.

if i manually run ip addr add 192.168.1.22/24 dev vmbr0. then i can reach the WEBUI of proxmox. The VM's and LXC's lose internet at this point.
Also on a reboot, this fails again.

1748780173475.png

the ip addresses for the proxmox server and the LXC's and VM's all have dhcp reservations in my synology router.

I have rebooted my router as well.

Please can someone help me fix this.

Much appreciated.
 
Last edited:
Afaik tailscale does add some firewall rules, if installed on the host - is it possible that the server started acting up after installing tailscale? Have you checked for duplicate IPs in your network?

What's the output of the following commands when your setup is not working?

Code: 
ip a
ip r
iptables -L
iptables -L -t nat
 
Thanks Stefan for helping.
I have tried disbling tailscalte service completely and restarted but the probelm still persists.

i have just ran:
Code: 
ip addr del 192.168.1.22/24 dev vmbr0
if reload -a -d
systemctl restart networking.services
reboot now

after the server rebooted, i have a constant ping going from my laptop on the same network to:
Proxmox server: 192.168.1.22 - Request Times Out
A VM inside Proxmox : 192.168.1.70 - Getting Replies from this

If i now run:
Code: 
ip addr add 192.168.1.22/24 dev vmbr0
then the Server will start replying to pings and the vm will start replying with "Request Timed out"

Code: 
root@proxmox: ~#ip a | head -n 23
1: 1o: <LOOPBACK, UP, LOWER_UP> mtu 65536 qdisc neueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:08:08:00:08 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: eno1: ‹BROADCAST, MULTICAST, UP, LOWER_UP> mtu 1500 qdisc pfifo_fast master vmbr0 state UP group default qlen 1000
    link/ether 00:xx:xx:xx:xx:xx brd ff:ff:ff:ff:ff:ff
    altname enp0s31f6
3: tailscaleß: <POINTOPOINT, MULTICAST, NOARP, UP, LOWER_UP> mtu 1280 qdisc pfifo_fast state UNKNOWN group default qlen 1500
    link/none
    inet 100.75.xx.xx/32 scope global tailscale0
       valid_lft forever preferred_lft forever
    inet6 fd7a:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx/128 scope global
       valid lft forever preferred_1ft forever
    inet6 feB0::xxxx:xxx:xxxx:xxxx/64 scope link stable-privacy
       valid_lft forever preferred_Ift forever
4: vmbr0: ‹BROADCAST, MULTICAST, UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 00:4e:xx:xx:xx:a5 brd ff:ff:ff:ff:ff:ff
    inet6 2a02:xxxx:xxxx:xxxx:xxx:xxxx:xxxx:xxxx/64 scope global dynamic mngtmpaddr
      valid_1ft 672534sec preferred_1ft 586134sec
    inet6 fe80::xxx:xxx:xxxx:xxxx/64 scope link
      valid_lft forever preferred lft forever

Code: 
root@proxmox: ~#ip r

Code: 
root@proxmox: ~# iptables -L
Chain INPUT (policy ACCEPT)
target        prot     opt     source        destination
ts-input    all      --      anywhere    anywhere

Chain FORWARD (policy ACCEPT)
target        prot     opt     source        destination
ts-forward     all     --         anywhere    anywhere

Chain OUTPUT (policy ACCEPT)
target        prot     opt     source        destination

Chain ts-forward (1 references)
target        prot     opt     source        destination
MARK        all     --         anywhere    anywhere      MARK xset 0x40000/0xff0000
ACCEPT        all     --         anywhere    anywhere    mark match 0x40000/0xff0000
DROP        all     --         100.64.0.0/10 anywhere
ACCEPT        all     --         anywhere    anywhere

Chain ts-input (1 references)
target        prot     opt     source        destination
ACCEPT        all     --         proxmox.example.ts.net anywhere
RETURN        all     --         100.115.92.0/23    anywhere
DROP        all     --         100.64.0.0/10    anywhere
ACCEPT        all     --         anywhere    anywhere
ACCEPT        udp     --         anywhere    anywhere    udp dpt: 41641

Code: 
root@proxmox: ~# iptables -L -t nat
Chain PREROUTING (policy ACCEPT)
target        prot     opt     source        destination

Chain INPUT (policy ACCEPT)
target        prot     opt     source        destination

Chain OUTPUT (policy ACCEPT)
target        prot     opt     source        destination

Chain POSTROUTING (policy ACCEPT)
target        prot     opt     source        destination
ts-postrouting all     --         anywhere    anywhere

Chain ts-postrouting (1 references)
target        prot     opt     source        destination
MASQUERADE     all        --         anywhere    anywhere    mark match 0x40000/0xff0000

the mindbollging thing is that without changing anything, after a while the VM ip also starts replying with "Request Timed out". restarting the network service, unplugging and replugging the network cable, doesnt resolve anything at this point. If i reboot, the vm is back to pinging again.
 
Last edited:
It is more likely than not that your tailscale is interfering with standard configuration, or possibly something else you experimented with.

Please disable tailscale, reboot your machine, then record the state of your network configuration, i.e.:
script network.txt
ip a
ip route
systemctl status networking.service
exit

If you vmbr0 interface does not show IPv4 address assigned - examine your boot log: journalctl -b0


Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox
 
Thanks.

I just did systemctl disable tailscale.services and rebooted the server

when i do
Code: 
ip a
i dont see tailscale anymore so thats definitely stopped.

ip route still doesnt return anything

systemctl status networking.service shows this error:

Code: 
• networking.service - Network initialization
Active: active (exited) since Mon 2025-06-02 17:42:15 BST; 3min 54s ago Docs:
man: inter faces (5)
man: i fup (8)
man: i fdown (8)
Process: 743 ExecStart=/us/share/i fupdoun2/sbin/start-networking start (code-exited, status=0/SUCCESS)
Main PID: 743 (code=exited, status=0/SUCCESS)
CPU: 448ms
Jun 02 17:42:14 proxmox systemd[1]: Starting networking.service - Network initialization...
Jun 02 17:42:14 proxmox networkingl743]: networking: Configuring network interfaces
Jun 02 17:42:15 proxmox networkingL940]: warning: cannot load "address" module: cannot import name 'splat' from 'jaraco.functools' (/usr/lib/python3/dist-packages/jaraco/functools.py)
Jun B2 17:42:15 proxmox /usr/sbin/ifup[940]: warning: cannot load "address" module: cannot import name 'splat' from 'jaraco.functools' (/usr/lib/python3/dist-packages/jaraco/functools.py)
Jun 02 17:42:15 proxmox systemd[1]: Finished networking. service - Network initialization.

so i then looked at this:
C

Thread 'Static IP Issues'

Has anyone run into this issue before?
It was working fine and I just rebooted it after installing CEPH and now I get this

I did a pveceph purge and it's gone now but I feel something was removed that shouldn't have been

systemd[1]: Starting networking.service - Network initialization...
networking[4249]: networking: Configuring network interfaces
networking[4264]: warning: cannot load "address" module: cannot import name 'splat' from 'jaraco.functools' (/usr/lib/python3/dist-packages/jaraco/functools.py)
/usr/sbin/ifup[4264]: warning: cannot load "address" module: cannot import name 'splat'...

i renamed the jaraco folder and restarted the networking service. The pings to the proxmox server started working but now the ping to the vm stopped.

so i have restarted the server and after a restart both pings are up. I re-enabled tailscale and restarted.

everything is working fine until now.

i will keep a look out to see if the vm's still stop pinging after a while wirthout me making any changes.
 
Last edited:
rbhalla said:
i will keep a look out to see if the vm's still stop pinging after a while wirthout me making any changes.
Click to expand...
Your system initially had a package issue that prevented the host IP address from being set during boot.

You discovered that manually assigning the IP address to the interface brought it online, which confirmed that the interface itself was functional.

You identified the root cause of the broken networking using logs and worked around it. However, services in Proxmox VE that had started while the network was in a failed state required a restart - this is expected behavior.

At this stage, you should focus on confirming that networking comes up cleanly on reboot, rather than monitoring an improbable transient issue on an already-booted system.

Good luck!

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox
 
  • Like
Reactions: rbhalla
You must log in or register to reply here.
Top Bottom