Read up on "--redirect-gateway" and options for it like "def1" and "bypass-dhcp".
This option "--redirect-gateway" allows you to have the VPN Server become responsible for traffic to the Internet. If you plan to have all of your clients (IPv4) traffic pass through the OpenVPN Server when connected, then it will need to act as a gateway/router for all your traffic. The default settings for windows is to NOT forward network traffic and act as a router. A common method to make this work for IPv4 is to enable IP Masquerading / NAT, on the OpenVPN Server. With Linux as the OpenVPN server, this can be done with "iptables" and with windows it may be possible by enabling "Internet Connection Sharing" for the interfaces involved.
if your intent is to NOT run all of your traffic through the VPN Server, but instead, only run traffic for a few networks through your OpenVPN server, and have all other traffic to the Internet NOT run through your OpenVPN server, then using that option ("--redirect-gateway") is probably not what you want.
If you plan to run all your traffic through the OpenVPN server, then you probably want something like:
push "redirect-gateway def1 bypass-dhcp"
(But read up on this and these options before using them to know what they are supposed to do. Also, if you plan to have all of your IPv4 traffic run through the OpenVPN Server, then Internet Connection Sharing may be needed unless there is another NAT box between your OpenVPN server and its access to the Internet to NAT your OpenVPN 10.10.0.0/24 network addresses with routing support for that network, too.)
When you wrote above that you are unable to ping the OpenVPN server, are you trying to ping the OpenVPN Server tunnel interface IP or another interface IP address? (more on this below...)
From this
server 10.10.0.0 255.255.255.0
I would guess your OpenVPN server probably is using 10.10.0.1 as its IP address on its Tunnel Interface. When your client is connected, it likely have some address on its tunnel interface as 10.10.0.X/24 . When your client is connected to the OpenVPN Server, from the client try to ping the OpenVPN Server Tunnel interface IP address:
From the client:
ping 10.10.0.1
If that works, then you really are able to ping the OpenVPN Server. (That would be good progress.)
If when you are able to ping 10.10.0.1 from the client (assuming the server is using 10.10.0.1) but you are not able to ping 192.168.10.2 from the OpenVPN client, then that suggests one of two issues on the OpenVPN server:
* Routing:
* Firewall/network filter.
If you enable Internet Connection sharing on the Windows OpenVPN Server, then that may include NAT rules to address the "routing" question and enable forwarding.
If you disable all your network filters/firewalls onthe Windows server (just for testing) that should help address that network firewall issue.
After that, try from the client to ping the 192.168.10.2 and see if it works. if that does work, then try re-enabling whatever firewall/network-filter rules you have and see if it still works.
If that works, then the issue was routing. Using Internet Connection Sharing in windows is a bit of a "big brick" to solve a routing problem. A more surgical solution might be to enable only specific routes using "real" routing, and not hiding the real source IP address(es.)
