pfSense

Hi,

I have configured DHCP Relay to listen on dedicated interfaces only (see pic).
The "GRUEN" interface is dedicated to a physical nic (192.168.1.254/24) and the other three are sharing a physical nic through VLAN configuration. VLAN configuration is fine and works like a charm.

So DHCP relay should NOT do anything on GRUEN interface because the dedicated DHCP server (192.168.1.10) is running in this LAN, too.

Unfortunately DHCP relay ignores the configuration on pfSense and reacts on queries on the GRUEN interface despite of its configuration. See the log entries from the (ICS) DHCP server:

Feb 22 08:29:05 praxis dhcpd⁸⁰⁹²: DHCPDISCOVER from 54:04:a6:a4:75:05 via eth0
Feb 22 08:29:05 praxis dhcpd⁸⁰⁹²: DHCPOFFER on 192.168.1.54 to 54:04:a6:a4:75:05 via eth0
Feb 22 08:29:05 praxis dhcpd⁸⁰⁹²: DHCPDISCOVER from 54:04:a6:a4:75:05 via 192.168.1.254
Feb 22 08:29:05 praxis dhcpd⁸⁰⁹²: DHCPOFFER on 192.168.1.54 to 54:04:a6:a4:75:05 via 192.168.1.254
Feb 22 08:29:05 praxis dhcpd⁸⁰⁹²: DHCPREQUEST for 192.168.1.54 (192.168.1.10) from 54:04:a6:a4:75:05 via eth0
Feb 22 08:29:05 praxis dhcpd⁸⁰⁹²: DHCPACK on 192.168.1.54 to 54:04:a6:a4:75:05 via eth0
Feb 22 08:29:05 praxis dhcpd⁸⁰⁹²: DHCPREQUEST for 192.168.1.54 (192.168.1.10) from 54:04:a6:a4:75:05 via 192.168.1.254
Feb 22 08:29:05 praxis dhcpd⁸⁰⁹²: DHCPACK on 192.168.1.54 to 54:04:a6:a4:75:05 via 192.168.1.254
Feb 22 08:29:08 praxis dhcpd⁸⁰⁹²: DHCPINFORM from 192.168.1.54 via eth0
Feb 22 08:29:08 praxis dhcpd⁸⁰⁹²: DHCPACK to 192.168.1.54 (54:04:a6:a4:75:05) via eth0
Feb 22 08:29:08 praxis dhcpd⁸⁰⁹²: DHCPINFORM from 192.168.1.54 via 192.168.1.254
Feb 22 08:29:08 praxis dhcpd⁸⁰⁹²: DHCPACK to 192.168.1.54 (54:04:a6:a4:75:05) via eth0

So you see the clients sends DHCPDISCOVER which is forwarded by the pfSense (192.168.1.254). Even though the DHCP server already has the original request. So in the end the cleint is re-requesting the IP addresse very frequently (configuread lease time is eight hours but the client rerequests the lease aproximaltey ever 4 mintues).

Especially some older devices can not deal whith thei and refuse to accept the lease.

So this is obviously a bug as the DHCP relay act on interfaces it should not to.