[Openvpn-users] Problem with --ifconfig endpoints under Windows

[Stole P. <amo...@gm...>]

Hi,
I just wrote a client config file for openvpn. The problem is this: I tried
running the config under Linux and is working great, it's connecting to the
server and everything is fine, but when I use the SAME config file for
windows, it gives me some strange errors, like this:

Wed Mar 14 08:31:02 2012 WARNING: Since you are using --dev tun, the second
argument to --ifconfig must be an IP address.  You are using something
(255.255.0.0)  that looks more like a netmask. (silence this warning with
--ifconfig-nowarn)
Wed Mar 14 08:31:02 2012 There is a problem in your selection of --ifconfig
endpoints [local=10.8.0.10, remote=255.255.0.0].  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' option for more info.
Wed Mar 14 08:31:02 2012 Exiting

I don't know what could be the problem, since the script is working
perfectly fine on Linux. I have some thoughts about this though:
1. Is it because the networking adapters in linux and windows are behaving
differently, so I need to add more options in the config file in order to
make it work for windows environments?
2. I was testing it on a windows virtual machine under virtualbox - at
first I thought it was because I used NAT networking, but when I switched
to Bridged Adapter mode and it gave me the same error, I don't really think
this is the issue, but it may be the case, I just don't know.

And also, here is the client config file I am using:

##############################
################
# Sample client-side OpenVPN 2.0 config file #
# for connecting to multi-client server.     #
#                                            #
# This configuration can be used by multiple #
# clients, however each client should have   #
# its own cert and key files.                #
#                                            #
# On Windows, you might want to rename this  #
# file so it has a .ovpn extension           #
##############################################

# Specify that we are a client and that we
# will be pulling certain config file directives
# from the server.
client

# Use the same setting as you are using on
# the server.
# On most systems, the VPN will not function
# unless you partially or fully disable
# the firewall for the TUN/TAP interface.
;dev tap
dev tun

# Windows needs the TAP-Win32 adapter name
# from the Network Connections panel
# if you have more than one.  On XP SP2,
# you may need to disable the firewall
# for the TAP adapter.
;dev-node MyTap

# Are we connecting to a TCP or
# UDP server?  Use the same setting as
# on the server.
;proto tcp
proto udp

# The hostname/IP and port of the server.
# You can have multiple remote entries
# to load balance between the servers.
remote x.x.x.x xxx
;remote my-server-2 1194
;remote 74.208.70.12 1359

# Choose a random host from the remote
# list for load-balancing.  Otherwise
# try hosts in the order specified.
;remote-random

# Keep trying indefinitely to resolve the
# host name of the OpenVPN server.  Very useful
# on machines which are not permanently connected
# to the internet such as laptops.
resolv-retry infinite

# Most clients don't need to bind to
# a specific local port number.
nobind

# Downgrade privileges after initialization (non-Windows only)
;user nobody
;group nobody

# Try to preserve some state across restarts.
persist-key
persist-tun

# If you are connecting through an
# HTTP proxy to reach the actual OpenVPN
# server, put the proxy server/IP and
# port number here.  See the man page
# if your proxy server requires
# authentication.
;http-proxy-retry # retry on connection failures
;http-proxy [proxy server] [proxy port #]

# Wireless networks often produce a lot
# of duplicate packets.  Set this flag
# to silence duplicate packet warnings.
;mute-replay-warnings

# SSL/TLS parms.
# See the server config file for more
# description.  It's best to use
# a separate .crt/.key file pair
# for each client.  A single ca
# file can be used for all clients.
ca ca.crt
#cert client1.crt
#key client1.key
#topology subnet

# Verify server certificate by checking
# that the certicate has the nsCertType
# field set to "server".  This is an
# important precaution to protect against
# a potential attack discussed here:
#  http://openvpn.net/howto.html#mitm
#
# To use this feature, you will need to generate
# your server certificates with the nsCertType
# field set to "server".  The build-key-server
# script in the easy-rsa folder will do this.
ns-cert-type server

# If a tls-auth key is used on the server
# then every client must also have the key.
;tls-auth ta.key 1

# Select a cryptographic cipher.
# If the cipher option is used on the server
# then you must also specify it here.
;cipher x

# Enable compression on the VPN link.
# Don't enable this unless it is also
# enabled in the server config file.
comp-lzo

# Set log file verbosity.
verb 3

# Silence repeating messages
;mute 20

auth-user-pass


If you could help me out with this, that would be great, thank you in
advance.