Page 1 of 1

OpenVPN on OpenWrt

Posted: Sat Jul 16, 2011 8:54 am
by lancebaynes
I want to make a step-by-step howto to how to manually configure openvpn under OpenWrt 10.03.

I'm almost fully done!

I just got a little bug@the end.

Can someone please help me, how has bigger knowledge in OpenVPN?

The howto/bug@at the end is here:

http://unix.stackexchange.com/questions ... on-openwrt

Thank you in anticipation!

have a nice weekend!

Re: OpenVPN on OpenWrt

Posted: Thu Aug 25, 2011 8:51 pm
by krzee
Sat Jul 9 13:14:21 2011 WARNING: potential route subnet conflict between local LAN [192.168.80.0/255.255.255.0] and remote VPN [192.168.80.1/255.255.255.255]
Your vpn subnet must be different than your LAN subnet.
# shared.key: [???]
The tls-auth directive adds an additional HMAC signature to all SSL/TLS handshake packets for integrity verification. Any UDP packet not bearing the correct HMAC signature can be dropped without further processing. The tls-auth HMAC signature provides an additional level of security above and beyond that provided by SSL/TLS.
# client1.csr: [???]
Certificate signing request. Basically this is a cert that has not been signed by the CA yet. In the most secure setups key signing would work like this: user generates a key and a csr, user sends csr to the CA, CA signs the csr and sends back a crt, then the user has his private key and crt, but nobody else ever had access to his private key.

I think your problem is related the the first error above, you need to use a different subnet for LAN than VPN. also, it looks like you're connecting to a local machine (192.168.1.1) which means you need to use the local flag to --redirect-gateway

heres what the manual says about redirect-gateway, look at the local flag:

Code: Select all

--redirect-gateway flags... 
 (Experimental) Automatically execute routing commands to cause all outgoing IP traffic to be redirected over the VPN. 

 This option performs three steps: 

(1) Create a static route for the --remote address which forwards to the pre-existing default gateway. This is done so that (3) will not create a routing loop. 

(2) Delete the default gateway route. 

(3) Set the new default gateway to be the VPN endpoint address (derived either from --route-gateway or the second parameter to --ifconfig when --dev tun is specified). 

 When the tunnel is torn down, all of the above steps are reversed so that the original default route is restored. 

 Option flags: 

local -- Add the local flag if both OpenVPN servers are directly connected via a common subnet, such as with wireless. The local flag will cause step 1 above to be omitted. 

def1 -- Use this flag to override the default gateway by using 0.0.0.0/1 and 128.0.0.0/1 rather than 0.0.0.0/0. This has the benefit of overriding but not wiping out the original default gateway. 

bypass-dhcp -- Add a direct route to the DHCP server (if it is non-local) which bypasses the tunnel (Available on Windows clients, may not be available on non-Windows clients). 

bypass-dns -- Add a direct route to the DNS server(s) (if they are non-local) which bypasses the tunnel (Available on Windows clients, may not be available on non-Windows clients). 

 Using the def1 flag is highly recommended.

Re: OpenVPN on OpenWrt

Posted: Thu Aug 25, 2011 9:10 pm
by krzee
oh i almost forgot...
when i setup a similar openwrt setup, i had to use -I for my forward rules, not -A
-I inserts in the beginning of the chain, -A appends to the end of it.
you probably need to do the same =]