DHCP relay issues

[amlanhldr]

Hello members,

Its an unexpected behavior from DHCP Relay agents I couldn't find solution by myself.

Situation: I have 4 vlans and vlan1 is being management one, having a freeradius box as a dhcp server. All 4 vlans have dhcp relay agents configured pointed to the freeradius box.
What I expect that clients on vlans will broadcast for DHCP and the requests will be forwarded to freerad with gateway ip (interface ip) of concerned vlan.
Case1: Sometimes vlan3 or vlan4 (not noticed for vlan2 yet) client dhcp-request is received at freerad box having vlan1 gateway ip and vlan1 Network-subnet.
In freerad, I've created conditions on gateway ip or network-subnet to assign right vlan group attributes, but these misleading gateway ip is creating trouble to proper group assignment.

Case2: After 24.1.6 update, dhcp-discovery packets from vlan1 clients, are received at freerad box having gateway ip 0.0.0.0 and network-subnet 0.0.0.0/32. "ps aux" says dhcrelay process stat "R" for vlan1.
When I hit restart of dhcrelay service for vlan1 from ui, all started working normal. Now gateway-ip is the interface ip and Subnet is the correct subnet of vlan1, as expected. "ps aux" shows dhcrelay stat as "I" for vlan1 now.

I don't understand the source of the issue.

[SMiTTY]

Having a similar issue with Business 24.4 release.

We have 3 VLANs (default, Vlan10 and vlan50).

We started seeing 169.254 ips on vlan10, but vlan50 was fine. My first thought was dhcp guarding on Unifi as we have had this blow up in the past in some environments.

Further investigations via `sudo nmap -e vlan10 --script broadcast-dhcp-discover` and `sudo nmap -e vlan50 --script broadcast-dhcp-discover` showed we were getting no response on vlan10.

I stopped/started the relay on Vlan10 and things started working again.

[amlanhldr]

I was testing with this and that. Narrowed down to move the freerad server to different vlan, where I didnt enable relay. That worked.

Seems like server and relay on same vlan is not permitted for some reason. Anyway I'm happy ...for now.