When I connect my Proxmox Server to LAN my Whole Internet Stops Works Need a fix

A

abubakarwander

New Member
Sep 17, 2025
2
0
1
Hey that's I hope you all guys are doing great I am just new to the proxmox.
Just starting set up my first proxmox server.
Server Pc is
HP Elitedesk 800 G4 TWR
I5 8500
32GB RAM
512gb ssd
1tb HDD

My network setup is

Main ISP router
> Tenda 8 Port gegabit switch
>>My work PC
>>Proxmox PC

The issue
The issue I am face is strange and I am unable to find solution.
Once I connect my Proxmox to lan via ethernet my whole internet goes down even proxmox is is shutdown.
Once I unplug it internet comes back.
Here what I have confirmed so far
Installed win 11 on prox pc works fine
So no issue in ethernet port or cables.
No conflict in ips at isp router
Here are the ips
My router ip 192.168.0.2 and preferred dns as well
My proxmox ip is 192.168.0.150:8006

My other devices at isp router has not same ip.

Please lads guide what is the issue what ai am missing or doing wrong.
Looking for a guide for fix.
 
Gegabit switch is basic switch doesn't have any ip interface.
1. Once I connect my Proxmox to switched Yes I can access web ui of proxmox through ip on my work pc just fine. Only issue happens that my internet as entire to my all devices including proxmox stops working.
2. Console on proxmox monitor display my proxmox ip
To login visit 192.168.0150:8006
3. Shutdown mean if my proxmox pc is even shutdown mean pc is off but Ethernet is still connected that issue of internet stays there unless its unplug proxmox completely.
 
So i assume this is your setup:


Code: 
                      Internet
                          |
                  +----------------+
                  |     Router     |
                  |   192.168.0.2  |
                  +----------------+
                          |
                          |
              +----------------------+
              |  Unmanaged L2 Switch |
              +----------------------+
                     /        \
                    /          \
   +---------------------+   +---------------------+
   |  Proxmox (PC1)      |   |  Workstation (PC2)  |
   |  192.168.0.150      |   |  192.168.0.123      |
   +---------------------+   +---------------------+

Based on your observations:

As long as your Proxmox-Node is connected to the switch port (independend of its power status on/off), you cannot reach your "internet"

Follow up questions:
  • Are you still able to ping 192.168.0.2 while the Proxmox LAN cable is connected to the switch (and your internet is "not working")?
  • What kind of ICMP reply do you receive?
  • Are your switch LEDs lit up?
  • When you have Windows 11 installed on the Proxmox node and you connect it to the switch (either powered on or off), nothing happens?
 
Last edited:
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