Routes to other networks not working


New Member
Jun 15, 2023
Calgary, AB, Canada
Hello! I'm running into networking problem with my proxmox guest VMs that I'm scratching my head over, and I'm hoping the community can help me out.

Here's my setup:
  • Router / default gateway / access point
  • / DHCP server, VPN server, other stuff
  • Proxmox server with a few VMs including windows 11 and linux (mostly ubuntu)
  • (Soon to be shut down) XCP-NG server with a few VMs
  • 192.168.0.x: Other clients
As you can see, is connected to two networks, and is responsible for routing traffic between them. I don't think it's important, but it's running zentyal. The router is just a home router, an Asus ZenWifi. On the router, there's a static route defined that specifies as the gateway for

Almost everything works great: all devices on the 192.168.10.x network can reach everything (including the VMs) on the 192.168.0.x network just fine. All the physical devices (including the proxmox server itself) and XCP-NG VMs on the 192.168.0.x network can reach everything on the 192.168.10.x network.

The problem is the proxmox VMs. None of them can reach the 192.168.10.x network at all, and I can't for the life of me figure out why. It's got to be proxmox, but with both the server and all the VMs sharing vmbr0 I'm having a tough time understanding why traffic from the server is routed correctly to the other network but traffic from the VMs is getting stuck somewhere. I haven't changed any firewall settings on the proxmox server. Maybe I need to to get this setup working?

When I try and ping a client on the 192.168.10.x network from one of the proxmox VMs I get 100% packet loss:
From _gateway ( icmp_seq=2 Redirect Host(New nexthop: (

Any help or guidance is greatly appreciated!
What are the IPs you configured inside the VM?

Please provide the output of ip r from inside the VM (Linux).

In addition, please provide the network config (cat /etc/network/interfaces) and the ip r of the PVE host.

Did you enable the firewall on your PVE/the VMs?
The IPs inside the VMs are assigned by DHCP. They're reserved addresses so they stay consistent.

ip r from inside one of the VMs:
default via dev ens18 proto dhcp src metric 100 dev docker0 proto kernel scope link src dev br-6a014a7c9e29 proto kernel scope link src dev ens18 proto kernel scope link src dev ens18 proto dhcp scope link src metric 100

/etc/network/interfaces from the pve host:
# 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

iface eno1 inet manual

iface eno2 inet manual

auto vmbr0
iface vmbr0 inet static
        bridge-ports eno1
        bridge-stp off
        bridge-fd 0

ip r from the pve host:
default via dev vmbr0 proto kernel onlink dev vmbr0 proto kernel scope link src

I haven't changed the firewall settings on either the host or any of the VMs.

I also need to correct something I said in my original post, that the pve host can reach the other networks just fine - it can reach the other networks but "just fine" turned out to be a stretch, and there's definitely something going on. On the host pinging a device on the other network seems to have a ~40% success rate (which I guess is better than 0% on the VMs, but still).

root@sybill:~# ping -c3 whirlwind
PING ( 56(84) bytes of data.
From ( icmp_seq=2 Redirect Host(New nexthop: (
64 bytes from ( icmp_seq=3 ttl=63 time=71.5 ms

--- ping statistics ---
3 packets transmitted, 1 received, 66.6667% packet loss, time 2024ms
rtt min/avg/max/mdev = 71.476/71.476/71.476/0.000 ms

I guess a potential solution would be to manually create the relevant route on the pve host and each of the VMs, but I'd really prefer to avoid doing that if I can. I plan to make changes to the setup in the future, so having the routes defined in a single spot (on the router) is attractive to me if it's possible.


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