We have a fortigate firewall in transparent mode. WAN interface is on VLAN 10 and INTERNAL interface is on VLAN 20. If I connect a server behind VLAN 20 on the switch where the firewall is connected everything works fine. The problem is when I connect to another switch that is getting VLAN 20 over a 802.1Q VLAN TRUNK. In this scenario the server cannot be reachable. I think this is related to ARP requests. Any lights on this?
Just to clarify, all server inside VLAN 20 are reachable within the VLAN. Just that firewall traffic from VLAN 10 to VLAN 20 is not reachable.
CISCO 3550, Fortigate 200B
December 20, 2011 9:11 PM
February 28, 2012 2:43 PM