Multi wan and DNS

[HeinFreis]

Hi Guys

I need advice, please. My network is giving me what I can only think is DNS related errors. Core Switch is the Router & DHCP server. Using a 100e Fortigate as the firewall. We have 3 active WAN’s. I also have 5 SSID each with its own VLAN #.

Current setup;

VLAN A – WAN 1

VLAN A – WAN 2

VLAN B – WAN 3

VLAN C – WAN 3

VLAN D – WAN 3

 Our offices are in China. We make use of a local ISP for WAN1 and WAN3 but also use the same ISP for a dedicated line to Hong Kong WAN 2.

The problem is that I need to direct all local traffic via WAN1 “baidu.com” and all “google.com” traffic via HK on WAN2. For the most part of this, it seems to be working but many users get errors when trying to resolve google.com.

I’m using route base policy’s for all 3 the WAN’s and Static route over WAN 2 for GW. WAN 1 also has a static route to the DNS of the local ISP. But still I get high DNS latencies from time to time and google not resolving. Its seem all the traffic is going to the right places its just DNS

Any advice on this would be great