New here. Having a problem with DHCP on VLAN

Started by Matt_K, December 03, 2023, 06:16:08 AM

Previous topic - Next topic
I just installed my OpnSense today. On my base LAN everything is working just fine. I also have a VLAN100 and I believe that DHCP is setup the same way as the LAN, but devices are not getting IP's.
The auto generated rules for DHCP seem to be in place. According to the DHCP logs seem to say that the device is being offered a lease. The devices says that it's not getting it. I can't seem to find any log of it in the rules logs. Any ideas?

In this log. The .100. is the new vlan and the .1. space is the standard LAN.

Informational   dhcpd   DHCPACK on 192.168.1.209 to d4:3a:2c:60:ec:92 (Pixel-8-Pro) via igb0   
Informational   dhcpd   DHCPREQUEST for 192.168.1.209 from d4:3a:2c:60:ec:92 (Pixel-8-Pro) via igb0   
Debug   dhcpd   reuse_lease: lease age 1014 (secs) under 25% threshold, reply with unaltered, existing lease for 192.168.1.209   
Informational   dhcpd   DHCPACK on 192.168.100.22 to 4a:4c:35:ea:c1:73 (Pixel-8-Pro) via vlan01.100   
Informational   dhcpd   DHCPREQUEST for 192.168.100.22 (192.168.100.1) from 4a:4c:35:ea:c1:73 (Pixel-8-Pro) via vlan01.100   
Informational   dhcpd   DHCPOFFER on 192.168.100.22 to 4a:4c:35:ea:c1:73 (Pixel-8-Pro) via vlan01.100   
Informational   dhcpd   DHCPDISCOVER from 4a:4c:35:ea:c1:73 via vlan01.100




Hi,

as usual when dealing with VLANs (there are a many newbies regarding VLANs):
When troubleshooting, start at the lowest level. before you try to fix higher level services such as DHCP.

Are you sure youre VLAN is set up correctly? I doubt it!
Have you configured your Switch to match the VLAN tag accordingly? Sure? check again!
For troubleshooting configure a device in the VLAN100 with a static IP and see if it can ping the OPNSesnse VLAN100 Interface. Does not work? Sure there are not firewall rules blockin this on the OPNSense interface? Otherwise fix you switch config!
If "ping" with static IP really works (again, I doubt it) there might be an issue with some Firewall rules blocking outgoing DHCP traffic. Which yould be very uncommon as long as you have not configured such a rule.

Summary:
Check your VLAN config, especially your switch.

/KNEBB

Thank you.
I had an unmanaged switch between one of my AP's and a managed switch. I had to follow the wires to find it.