OpenVPN route missing

Question

I can connect to an OpenVPN server from Windows without any problems.

But when I try to connect from Ubuntu 12.04 (start OpenVPN) I receive the following:

OpenVPN needs a gateway parameter for a --route option and no default was specified by either --route-gateway or --ifconfig options

SERVER IP: 161.53.X.X internal network: 10.0.0.0 / 8

What I need to do ?

client configuration:

client
dev tap
proto udp
remote 161.53.X.X 1194
resolv-retry infinite
nobind

ca ca.crt
cert client.crt
key client.key

ns-cert-type server

comp-lzo

verb 3 server conf:

local 161.53.X.X
 port 1194
 proto udp

 dev tap
 dev-node OpenVPN

 ca ca.crt
 cert server.crt
 key server.key  # This file should be kept secret

 dh dh1024.pem

 # DHCP leases addresses to clients
 server-bridge

 # Push routes to the client to allow it
 # to reach other private subnets behind
 # the server.  Remember that these
 # private subnets will also need
 # to know to route the OpenVPN client
 # address pool (10.8.0.0/255.255.255.0)
 # back to the OpenVPN server.
 push "route 10.0.0.1 255.255.0.0"

 client-to-client

 duplicate-cn

 keepalive 10 120

 comp-lzo
 verb 6

log from Ubuntu client:

[Server] Peer Connection Initiated with [AF_INET]161.53.XX.XX:1194

SENT CONTROL [Server]: 'PUSH_REQUEST' (status=1)

PUSH: Received control message: 'PUSH_REPLY,route 10.0.0.1 255.0.0.0,redirect-gateway def1,route-gateway dhcp,ping 10,ping-restart 120'

OPTIONS IMPORT: timers and/or timeouts modified

OPTIONS IMPORT: route options modified

OPTIONS IMPORT: route-related options modified

ROUTE default_gateway=161.53.XX.1

OpenVPN needs a gateway parameter for a --route option and no default was specified by either --route-gateway or --ifconfig options

OpenVPN ROUTE: failed to parse/resolve route for host/network: 10.0.0.1

TUN/TAP device tap0 opened

TUN/TAP TX queue length set to 100

NOTE: unable to redirect default gateway -- VPN gateway parameter (--route-gateway or --ifconfig) is missing

Initialization Sequence Completed

Solution 1

Your client config mentions server-bridge, so you are running a DHCP server which is bridged on the server-side. The DHCP server should provide the client with an IP address and a subnet. The client should then automatically route all traffic over this subnet through the VPN interface. I therefore think that your route command is redundant and you can just as well remove it.

Also, you mention your network is 10.0.0.0/8, but your config says push "route 10.0.0.1 255.255.0.0" which is /16.

You probably don't need to set a gateway if you don't route within 10.0.0.0/8, and if you do you can set it using the DHCP server. Manually setting the IP address using ifconfig should not be necessary either.

Solution 2

I'd look at 2 things. First, check your OpenVPN logs, that'll give you more information. I'm going from memory but I think it'll be in ~.

Also, check the Ubuntu firewall settings to be sure that this traffic can get through.

iptables -L

That'll show you the current set of rules.

-- edit

Your log files show that you don't have a gateway defined. According to OpenVPN docs you need to create a config.ovpn file and specify its location.

openvpn --config client.ovpn

You'll address the gateway issue by specifying the route, which is done by including these lines (updated to your network settings, of course). [Source]

ifconfig 10.0.X.X 255.255.255.0

route-gateway 10.0.0.1

Also, its considered bad form or a faux pas to post your question in two Stack Exchange forums.

Comments

[dajuric]

When I run iptables-L everything is accepted (there is no DROP rule).

[dajuric]

Why Windows client successfully extracts address from DHCP server and Linux client don't ? Is there something wrong with a gateway (do I need to tell the client what is gateway - look the log above) ?

[Lenwood]

This is most likely an configuration issue with your Ubuntu system. I doubt that it has anything to do with your network or the OpenVPN system itself. See my updated solution for more info.

[dajuric]

Yes, those instructions that you wrote say that I want to set my IP address. Right ? But my address need to be leased from DHCP. When a client is connected to a server, internal DHCP leases address for it. That works for Windows, but not for any Ubuntu that I have tried.

[Lenwood]

The gateway address will never change. For your network that should be 10.0.0.1 (according to your file above). For the computer's IP address, you have 2 ways to go. First, you could reserve an IP address for your Ubuntu machine (this is what I do for wifi printers on my network). Or second, you could write a script that detects your IP then updates this text file. If I were you I'd go with the first option. Choose an IP toward the end of the available range to ensure that there won't be any conflicts. Ubuntu is fantastic, but it can definitely take more effort to configure.

[dajuric]

Thank you! I already solved the problem, but still thank you for the answer.

[Gustavo Rubio]

@dajuric How did you solved it? I'm struggling myself too with OpenSuSE, same issue