XGS1930 - Log information

AlbertoB77

I have am XGS1930 installed on machine. I have this log entry:

4 Feb 03 14:00:47 IN dhcp: Duplicated subnet configuration on interface Vlan 1, IP 192.168.127.166/24, DHCP server 192.168.127.172

What does it mean?

192.168.127.172 is the ip address of central pc of the machine (this is a Debian 12 machine with dhcp server).

Thanks

Alberto

Zyxel_Tina

Hi @AlbertoB77,

Welcome to the Zyxel Community!

We have reproduced the issue, and the log message appears when the switch has multiple IP interfaces configured on the same VLAN, for example:

• One IP interface is configured as Static
• Another IP interface on the same VLAN is obtained via DHCP
• And both IP interfaces belong to the same subnet

In this case, the switch detects that two IP interfaces on VLAN 1 share an identical subnet, which triggers the log message you observed.

Therefore, please check whether your XGS1930 really needs multiple IP interfaces on VLAN 1.

• If you are only using a Static IP on VLAN 1, please remove the second IP (the DHCP-assigned one).
• If you intend to use DHCP only, remove the Static IP entry and keep only the DHCP interface.

Having two IP interfaces in the same VLAN and subnet is not recommended and may lead to unexpected behavior. (Feel free to share your IP interface configuration screen, and we can help confirm the correct setup.)