[SOLVED] Can't connect to proxmox server directly using an ethernet cable from my pc but CAN connect IF proxmox server is connect to my router

nefero

New Member
May 7, 2022
2
0
1
Ok, this seems really silly, but I am really out of ideas...

I have a 6 port mini computer that works well with OPNSense but I wanted to use OPNSense in proxmox and replace my old router/switch.

It happens that during its configuration (when it's connected to my router), I can connect via web and SSH normally (and ping). BUT when I try to connect directly from my PC to proxmox, I can't.

Just to create a first summary:
  • My PC has a static address of 192.168.1.100/24
  • My proxmox ve server is at 192.168.1.4/24 (vmbr0)
  • I have 5 of my 6 interfaces in vmbr0 and I can plug my router cable to any of these ports that I will be able to connect from my PC.

This is my /etc/network/interfaces file:
auto lo
iface lo inet loopback

auto enp9s0
iface enp9s0 inet manual
#ETH6

auto enp1s0
iface enp1s0 inet manual
#ETH1 (WAN)

auto enp2s0
iface enp2s0 inet manual
#ETH3

auto eno1
iface eno1 inet manual
#ETH2

auto enp7s0
iface enp7s0 inet manual
#ETH4

auto enp8s0
iface enp8s0 inet manual
#ETH5

auto vmbr0
iface vmbr0 inet static
address 192.168.1.4/24
gateway 192.168.1.1
bridge-ports enp9s0 eno1 enp2s0 enp7s0 enp8s0
bridge-stp off
bridge-fd 0
#Management

And this is the dmesg of my 'official' management port, enp9s0.
dmesg | grep -E "enp9s0|eth0"
[ 1.853173] igc 0000:01:00.0 eth0: MAC: 00:e2:69:12:24:ac
[ 2.467063] igc 0000:09:00.0 enp9s0: renamed from eth5
[ 2.481603] igc 0000:01:00.0 enp1s0: renamed from eth0
[ 5.935146] vmbr0: port 1(enp9s0) entered blocking state
[ 5.935155] vmbr0: port 1(enp9s0) entered disabled state
[ 5.935313] device enp9s0 entered promiscuous mode
[ 9.522794] igc 0000:09:00.0 enp9s0: NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX/TX
[ 9.523995] vmbr0: port 1(enp9s0) entered blocking state
[ 9.524025] vmbr0: port 1(enp9s0) entered forwarding state
[ 89.350105] igc 0000:09:00.0 enp9s0: NIC Link is Down
[ 89.350379] vmbr0: port 1(enp9s0) entered disabled state
[ 98.815072] igc 0000:09:00.0 enp9s0: NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
[ 98.924857] vmbr0: port 1(enp9s0) entered blocking state
[ 98.924894] vmbr0: port 1(enp9s0) entered forwarding state
[ 258.264974] igc 0000:09:00.0 enp9s0: NIC Link is Down
[ 258.265229] vmbr0: port 1(enp9s0) entered disabled state
...

*I remember that we used to mind patch and cross-over cables when connecting two devices from the same layer, but I don't think it applies nowadays as I can connect directly IF I install OPNSense instead of proxmox, but MAYBE, there is something in the OS I should mind?

Anyway, I am not using fancy VLAN or anything like this. The most fancy thing I tried, was to use a different bridge to use the VMs but, ultimately, I wanted to:

  • Be able to access the management from any interface as this mini pc will be my router/switch (using a virtualized OPNSense instead);
  • Launch an OPNSense VM,assign it to a bridge so I can connect directly from my PC independent of the port I am connecting phisycally
  • Launch a pi-hole CT, assign it to a bridge so I can connect directly from my PC independent of the port I am connecting physically;
I am thinking I am doing something very unusual as I couldn't see any similar scenario to mine, but still, I would really appreciate if I can get any insight from you.

Thank you!
 
Last edited:

nefero

New Member
May 7, 2022
2
0
1
Sorry, my bad.
Apparently it was ARP. I tested with another computer, and it worked.
After I cleaned ARP in my Windows PC with 'arp -d *' it started working.
 

About

The Proxmox community has been around for many years and offers help and support for Proxmox VE, Proxmox Backup Server, and Proxmox Mail Gateway.
We think our community is one of the best thanks to people like you!

Get your subscription!

The Proxmox team works very hard to make sure you are running the best software and getting stable updates and security enhancements, as well as quick enterprise support. Tens of thousands of happy customers have a Proxmox subscription. Get your own in 60 seconds.

Buy now!