OpenVPN DNS question

[rlcronin]

Got my n66u setup with OpenVPN and everything worked great until I noticed that my OpenVPN-for-Android client could not resolve Internet hostnames. I solved that by forcing the client to override the DNS settings received from the server, but I am curious why that is necessary. The server was doling out two DNS server addresses to the client, 192.168.1.1 and 208.67.222.222 (the latter being the OpenDNS server I configured in the LAN->DHCPServer->DNSandWINSServerSetting->DNSServer field in the router config). Ideas?
--
bc

 

[RMerlin]

Make sure you enable "Advertise DNS to clients" on the router. If it still doesn't work then it must be a limitation of the Android client, because that option works fine for me with the WIn32 OpenVPN client.

 

[rlcronin]

Indeed, "Advertise DNS to clients" is set to yes. I checked on the phone to see what DNS servers it had after starting the VPN session and it had what I expected, 192.168.1.1 and 208.67.222.222 (in that order). I was wondering, though, how that works exactly as the IP address the phone gets is 10.8.x.x. How does it get from there to 192.168.1.1? Is there a route generated somewhere that takes care of that? I was thinking maybe it wasn't working because it was trying to get to 192.168.1.1 and could not (though why it wouldn't then failover to 208.67.222.222 I don't know).
--
bc

 

[rlcronin]

Here's the config file the client generates, for what its worth. See anything wrong in this?

suppress-timestamps
client
verb 1
connect-retry-max 5
resolv-retry 5
dev tun
remote xxxxxxxx.asuscomm.com 1194 tcp-client
comp-lzo
route 0.0.0.0 0.0.0.0
tls-remote n66u
remote-cert-tls server
cipher AES-128-CBC

That route 0.0.0.0 0.0.0.0 looks vaguely suspicious ...
--
bc

 

[RMerlin]

Indeed, "Advertise DNS to clients" is set to yes. I checked on the phone to see what DNS servers it had after starting the VPN session and it had what I expected, 192.168.1.1 and 208.67.222.222 (in that order). I was wondering, though, how that works exactly as the IP address the phone gets is 10.8.x.x. How does it get from there to 192.168.1.1? Is there a route generated somewhere that takes care of that? I was thinking maybe it wasn't working because it was trying to get to 192.168.1.1 and could not (though why it wouldn't then failover to 208.67.222.222 I don't know).
--
bc

Under Windows, a static route gets pushed to the client, ensuring that it can access the router by its 192.168.xx.xx IP. No idea about the Android client.