I've setup an OpenVPN server with the following network settings:
topology subnet server 192.168.123.0 255.255.255.0 push "dhcp-option DNS 192.168.123.1" # DNS to server VPN IP push "route 192.168.2.0 255.255.255.0" # Workstations addresses via VPN keepalive 10 120
- 192.168.2.* = company LAN
- 192.168.123.* = VPN LAN
Linux clients are able to connect, but a Windows 7 system fails with the following error:
There is a problem in your selection of --ifconfig endpoints [local=192.168.123.2, remote=255.255.255.248]. The local and remote VPN endpoints must exist within the same 255.255.255.252 subnet. This is a limitation of --dev tun when used with the TAP-WIN32 driver. Try 'openvpn --show-valid-subnets' ....
This is the full output from the moment the connection initialized:
Thu Jul 01 09:36:55 2010 [server.FOOBAR] Peer Connection Initiated with 84.80.YYY.ZZZ Thu Jul 01 09:36:56 2010 SENT CONTROL [server.FOOBAR]: 'PUSH_REQUEST' (status=1) Thu Jul 01 09:36:56 2010 PUSH: Received control message: 'PUSH_REPLY,route 192.168.2.0 255.255.255.252,dhcp-option DNS 192.168.123.1,route-gateway 192.168.123.1,topology subnet,ping 10,ping-restart 120,ifconfig 192.168.123.2 255.255.255.248' Thu Jul 01 09:36:56 2010 Options error: Unrecognized option or missing parameter(s) in [PUSH-OPTIONS]:4: topology (2.0.9) Thu Jul 01 09:36:56 2010 OPTIONS IMPORT: timers and/or timeouts modified Thu Jul 01 09:36:56 2010 OPTIONS IMPORT: --ifconfig/up options modified Thu Jul 01 09:36:56 2010 OPTIONS IMPORT: route options modified< al>Thu Jul 01 09:36:56 2010 OPTIONS IMPORT: --ip-win32 and/or --dhcp-option options modified Thu Jul 01 09:36:56 2010 WARNING: Since you are using --dev tun, the second argument to --ifconfig must be an IP address. You are using something (255.255.255. 248) that looks more like a netmask. (silence this warning with --ifconfig-nowarn) Thu Jul 01 09:36:56 2010 There is a problem in your selection of --ifconfig endpoints [local=192.168.123.2, remote=255.255.255.248]. The local and remote VPN endpoints must exist within the same 255.255.255.252 subnet. This is a limitation of --dev tun when used with the TAP-WIN32 driver. Try 'openvpn --show-valid-subnets' ....
Any attempt to change the server settings to a 252 range results in the following error:
Options error: --server directive when used with --dev tun must define a subnet of 255.255.255.248 (/29) or lower
What server settings do I need to set to make this client connect? The server runs OpenVPN 2.1.1, the Windows 7 client runs OpenVPN 2.0.9 (latest stable from http://openvpn.se)
@Evan: This is my client config, not very exciting:
client dev tun proto tcp remote 18.104.22.168 1194 resolv-retry 2 nobind # Server keys ca SERVER-ca.crt tls-auth SERVER-ta.key 1 # Client key cert SOMEONE.crt key SOMEONE.key # Server settings to copy comp-lzo # Downgrade privileges after initialization (non-Windows only) user nobody group guest # Try to preserve some state across restarts. persist-key persist-tun # Verify server ns-cert-type server verb 3 ;cipher x ;mute 20 ;mute-replay-warnings