Ubuntu LXC on VLAN 25 gets IP but can’t ping gateway

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Oct 19, 2025
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I’m running Proxmox and an Ubuntu LXC on the same VLANs. Here’s the situation:

• VLAN 1 works fine — LXC can get an IP, ping the gateway, and reach the internet.

• Ubuntu LXC on VLAN 25 gets an IP, but I cannot ping the gateway (192.168.25.1) or any external IPs.

Some details about my setup:
• Proxmox bridge: vmbr0 (VLAN 1 default gateway is set here)

• LXC network config: net0: name=eth0,bridge=vmbr0,tag=25,ip=dhcp

• VLAN 25 is tagged on port 1 of the router and port 2 of the Proxmox server

• Proxmox firewall is enabled, but I have no rules:

Below is OPNsense firewall rule

Action: Pass
Quick: Apply the action immediately on match
Interface: TEST
Direction: in
TCP/IP Version: IPv4
Protocol: any
Source: any

So traffic should not be blocked.