AsusWRT, allowing single applications to bypass VPN client?

[lbnp]

Hi, I have my current AsusWRT configuration (on an RT-AS86u router) set to route all traffic through a VPN service using an OpenVPN client.

I want Zoiper Pro to not be routed through the VPN client. Is it possible to exclude a single application? I have searched the settings but come up short so far.

PS: I would prefer to stay with the stock firmware instead of Merlin if possible.

 

[Butterfly Bones]

I don't think you can with stock AsusWRT, sorry I missed that is your preference.

Yes, you can with Policy Based Routing. See this article on the RMerlin AsusWRT wiki. Note it has great examples near the bottom.

Policy based routing

Third party firmware for Asus routers (newer codebase) - RMerl/asuswrt-merlin.ng

github.com

 

[lbnp]

Thanks, that is unfortunate to hear. Looks like I'll need a new device for phone calls then.

 

[eibgrad]

You can't route a specific application through the VPN, because the only criteria available to PBR (policy based routing) is based on the source IP. So wrt that source IP, it's all or nothing in terms of what gets routed over the WAN vs. VPN.

However, if it happens that a given application is *known* to use specific public destination IPs, you could add static routes for those IPs to the OpenVPN client config and bind them to the WAN.

route 199.199.199.199 255.255.255.255 net_gateway

Of course, this affects *all* clients that use that destination IP, not just that one app on that one device.

If there are multiple destination IPs, and they belong to a common class (e.g., class C, 199.199.199.0/24), you could treat the class as a single route.

route 199.199.199.0 255.255.255.0 net_gateway