Dual routing on different WAN

[lluca]

Hi, i have the following situation:

WAN1 IP Gateway is 10.10.2.1/24 Wan2 IP Gateway is 10.10.1.1/24 INTERNAL_LAN 192.168.1.0/24 GUEST_LAN 10.1.1.0/24 I'm trying to make computers on INTERNAL_LAN access the internet using WAN1 and GUEST_LAN to WAN2. I created 2 static routes as below: 0.0.0.0/0.0.0.0 Gateway 10.10.2.1 on device WAN1 0.0.0.0/0.0.0.0 Gateway 10.10.1.1 on device WAN2 both having distance 10 and priority 0 2 policies are created, INTERNAL_LAN to WAN1 and GUEST_LAN to WAN2, ALL allowed

When I connect only WAN1, the computers on INTERNAL_LAN can access internet -> OK When I connect only WAN2, the computers on GUEST_LAN can access internet -> OK When I connect WAN1 and WAN2, the computers on GUEST_LAN can access internet via WAN2, but INTERNAL_LAN can't access via WAN1 -> PROBLEM Why ?

Thank you for any help Luca

[jintrah_FTNT · Accepted solution]

Hi Luca,

The problem is because of ECMP (Equal Cost Multi-Path), traffic is load balanced across the links (Please check this http://kb.fortinet.com/kb/microsites/search.do?cmd=displayKC&docType=kc&externalId=11292). Traffic from internal lan may have been tried to load balanced and pushed out of wan2, but since there is no policy, the traffic was getting denied, and it would not fallback to a different available route/policy  But as you desired, traffic flow should be by use of wan1 for internal lan network, and wan2 for guest network, this can be achieved with policy routes (please see http://kb.fortinet.com/kb/microsites/search.do?cmd=displayKC&docType=kc&externalId=100116)

Hope that helps.

Regards,

ranjith