Fortinet Client 5.6 override DNS settings - how to get name resolution for internal hosts?

[jacquesrk]

Environment: Fortinet Client 5.6.0.1075

Windows 7 Professional SP1 64-bit

On our network, we have a local DNS (IP address A.B.C.x) that resolves names like compa.mycompany.com to the correct IP address.

Our customer wants us to use Forinet Client to VPN to their machine.

After I open the VPN connection, I can access serv34.mycompany.com via IP address but no longer via name. I can however access serv57.customer.com successfully via name, which of course is what we want.

How do I work around this issue of being unable to access my own internal servers by name? (Besides putting all our mycompany.com servers in my local hosts file)

In the example below, A, B, C, D, E, x represent numbers in the IP address

Before I start the Fortinet client, "ipconfig /all" shows me this

Default Gateway . . . . . . . . . : A.B.C.1

DHCP Server . . . . . . . . . . . : A.B.C.1 DNS Servers . . . . . . . . . . . : A.B.C.x    A.B.C.x+1    A.B.C.x+2

After I start the Fortinet client, "ipconfig /all" shows me this (our internal DNS still show, but are preceded by the customer's DNS)

Default Gateway . . . . . . . . . : A.B.C.1 DHCP Server . . . . . . . . . . . : A.B.C.1 DNS Servers . . . . . . . . . . . : A.D.E.1    A.D.E.2    A.B.C.x    A.B.C.x+1    A.B.C.x+2

[Toshi_Esumi]

Is the VPN server at your customer a FortiGate that you have control or something else? It's the server side injecting those DNS IPs over vpn.

[jacquesrk]

I have no control over the VPN server at the customer site.

[Toshi_Esumi]

You might want to try disabling mode config (under Advanced Settings->VPN Settings) on the FortiClient side but it likely requires manual config on your PC/Mac side including static routes toward the tunnel.

I would at least ask whoever set the VPN up to change the config, or create a new VPN only for you, not to inject DNS IPs.

[jacquesrk]

Except that we need the customer's DNS to resolve names of the customer's servers.