DHCP uses IP Address Conflict Detection

[janw.zc]

Hello,
can anybody please tell me if the DHCP-Server used IP Address Conflict detection? Meaning if e.g. User PC1 assigned himself manually an IP from the DHCP Range and PC2 requests an IP from the DHCP and the one from PC1 would be the next to be offered - does the DHCP-Service make a ping to check if it might be in use although it should be free or does he simply assign it and create a duplicate IP?

Thanks in advance,

Jan

[Arakangel Michael]

Hi Jan,

I don't believe it does. I haven't seen anything in the documentation, or the web GUI for either OpnSense, or pfSense. Generally conflict detection is available for DHCP servers, but not on by default:

https://doc.pfsense.org/index.php/DHCP_Server

There is a line in this file:
/var/dhcpd/etc/dhvpd.conf

update-conflict-detection false

https://forum.opnsense.org/index.php?topic=850.0

You may be able to set that to 'true' to turn it on?