How to route Win7 VPN client traffic through alternate gateway

Question

I have two gateways, one chosen for speed and one chosen for volume, for cost considerations.

I use the Windows7 L2TP over IPSec VPN client to connect to work and I want to route this traffic though one gateway and the rest of my machine's traffic through the other gateway. I have set up static routes to send my work traffic through the VPN but the VPN then routes through the machines default gateway (.254) rather than the alternate (.253).

I can't find any way to configure the VPN client to use a different local gateway for it's cloud end. I guess there must be a ROUTE command but I can't work it out.

Any help appreciated.

Answer 1

I finally bumbled into my own answer:

I've been using 'NetRouteView' which is a free downloadable GUI utility to simplify access to the routing table and avoid using the ROUTE command in a cmd window.

1. Add the second gateway in the IP4 advanced properties of the network card. Here they are on my local subnet

        192.168.1.254 (original landline router - unlimited use)
        and 
        192.168.1.253 (new, limited volume 4G router)  

Each gate-way will add some lines to the routing table, for instance to handle low priority priority packets (I think) that look ike this:

  Destination        Netmask          Gateway       Interface  Metric
    0.0.0.0          0.0.0.0    192.168.1.253    192.168.1.104    266
    0.0.0.0          0.0.0.0    192.168.1.254    192.168.1.104    210

                     (My local PC is on port     192.168.1.104)

2. Now we need to add a line to direct our (priority) VPN packets via the 253 gateway

   nnn.nnn.nnn.nnn  255.255.255.255    192.168.1.253    192.168.1.104     11

    nnn.nnn.nnn.nnn  IP address of your remote VPN server
    255.255.255.255  makes the route specific to this single address.

That works for me. The only issue I now have is that after a reboot or waking from sleep the nnn line changes the gateway to the 254 address and I have to delete and re-enter it. If I edit it, NetRouteView complains 'Element not found'. I have the line set as 'persistent or 'Don't Change' but the problem, rather than the line, persists.