DHCP Server doesn't respond on requests

[user4000]

Hi All,

I'm completely new to OPNSense, trying to setup a standard home network ISP Modem -> Router -> Switch -> Multiple Stuff. I was able to setup everything as needed - LAN, WAN, Internet is connected, but the problem I have is DHCP.

For the simplicity and cleannes sake I reduced the setup to ISP Modem -> Bare metal OPN Sense -> PC. No VLANs, no IPv6, just a bare minimum setup, OPNSense v 24.7 (Although, I tried 25.Xs with the same result). If I set the PC's IP manually statically to 192.168.10.X - it works fine, has the Internet, WebGUI available. However, when I turn DHCP on the client PC on, it fails to obtain the IP address. According to DHCP server log, it believes that it sends DHCPOFFER back. However, according to OPNSense's own Firewall log, only the incoming DHCPDISCOVER happens. I even recorded packets on the client PC Wireshark - it also only see the DHCP DIscover 0.0.0.0:68 -> 255.255.255.255:67.

Quite possibly this is a misconfiguration of the firewall (see the rules screenshot), but can't figure out what exactly. I explicitly added "allow all outbound" on lan interface - doesn't help. I would appreciate any help - Thanks a lot in advance.

[Monviech (Cedrik)]

In a fresh new bare metal setup right after installation, a PC connected to the LAN port should get an IP address right away.

I would start totally fresh and if it does not work, it means there is a hardware level issue with your bare metal appliance regarding DHCP broadcasts.