I have a nomadix box connected over a trunk port on the core switch. following s the configuration.
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 132,150,151
switchport mode trunk
Nomadix box assigns the IP Addresses for the vlans 132, 150 and 151.
However, I find that for one other vlan (110), the Clients get IP Address from the Nomadix box vlan 150 scope.(this scope is marked as default in the nomadix box). when i shut the trunk port, clients in vlan 110 get ip from the DHCP server placed in the DMZ (which is the intended behaviour) however when the trunk port is up, again the clients get IP from the nomadix box.
can anybosdy help on this?
I would suggest to try to find out is somewhere in the network one of the permitted vlans (probably vlan 150) is joined to vlan 110 for example by connecting two access ports one in vlan 150 and one in vlan 110.
if so the broadcast DHCP request could reach the nomadix
it may be also a server bridging between two NICs
to find out where the L2 path between Vlans is I would do the following:
put a PC in vlan 110 and boot it as soon as it gets an ip address from Nomadix look for nomadix MAC address in CAM table in vlan 110 following that MAC address will lead to the port that connects the two vlans.
if you use a laptop with wireshark/ethereal on it you can capture the DHCP answer and you can check the source MAC address
Hope to help