OpenVPN MASQ SOURCE NAT When Not On Default Gateway

nettogrof

I'm a little confused at this and just need someone to explain it better to me.

I finally put OpenVPN on a dedicated server in our LAN because of the horrible performance on the EdgeRouters. Anyways, I hate NAT and can't wait for IPv6 so when it was on the Gateway everything was setup to avoid NAT and just use routing.

When moved behind the gateway on 10.10.10.146/24, I have to source NAT the VPN network 192.168.3.0/24 to the eth0 address 10.10.10.146 using MASQ of course in order for the VPN clients
to communicate with internal networks.

Without the source NAT rule on the OpenVPN server, VPN clients are unable to communicate to internal devices. However, internal devices can communicate with any VPN cilent device. EX: 10.10.10.8 pings 192.168.3.6 and will get a reply. So obliviously both ends know how to reach each other. (Push routes for VPN setup fine. Route to VPN network is in default gateway) However, if 192.168.3.6 pings 10.10.10.8, there's a timeout. Unless I masq 192.168.3.x as 10.10.10.146, I am unable to start communication from the VPN network. I have a feeling it is a weird routing issue, as in... I come from 192.168.3.6 to 10.10.10.8. I reach 192.168.3.1, then exit 10.10.10.146 to my destination 10.10.10.8. When 10.10.10.8 replies, it doesn't take the same path. 10.10.10.8's reply goes to the default gateway first 10.10.10.1, then back to 10.10.10.146, then should exit 192.168.3.1 to source 192.168.3.6.

Am I wrong on this? Am I right and it just doesn't work well?

I'd like one of you OpenVPN experts to help me out on this. It is bothering me.

Traffic

nettogrof wroteEX: 10.10.10.8 pings 192.168.3.6 and will get a reply. So obliviously both ends know how to reach each other. (Push routes for VPN setup fine. Route to VPN network is in default gateway) However, if 192.168.3.6 pings 10.10.10.8, there's a timeout. Unless I masq 192.168.3.x as 10.10.10.146

Perhaps the firewall @ 10.10.10.8 blocks incoming packets from foreign networks ..