Pushing IPV6 configuration to a client not supporting IPV6

pette_rsson

I am connecting to a VPN provider that supports IPV6. My configuration does not support it, and I just want the IPV4 setup.

On connect, the server pushes routes and ifconfig with IPv6 data to the client and making it crash.

I have not specified tun-ipv6 in the client configuration, and I got a warning about that the server and client config does not match. But shouldn't it be enough to not specify this option in the client config to make it ignore IPv6 commands pushed by the server?

Is it totally impossible to connect to a IPv6 ready server with a IPv4 only client? If not, how can I make it ignore the pushed commands?

janjust

you can prevent the pulling of routes using

route-nopull

you can overrule the pulling of *anything* by not specifying "client" in the client config; specify

tls-client

instead; you will be responsible for setting up the link , however.

An alternative is to use an "up" script and use

ifconfig-noexec

to have openvpn not automatically bring up the interface.

pette_rsson

OK, thank you. I guess that is an option, but I want some routes (all IPv4 routes) and the IPv4 IP, so I would have to make a more or less intelligent script then.

Would it be possible to make openvpn ignore this error;
Linux ifconfig inet6 failed: external program exited with error status: 1
and continue? That would solve my issues as well.

janjust

you'll have to use

ifconfig-noexec
up /etc/openvpn/ipv4-up.sh

this scrilpt will be called with parameters

tun/tap-dev tun-mtu link-mtu ifconfig-local-ip ifconfig-remote-ip

and perhaps a few more, so the script needs to do something like

#!/bin/bash

/sbin/ifconfig $1 $4 $5 mtu $2

pette_rsson

Yes, thank you.

Which and in what order of parameters is the route script called with? How would an example of a route script look?

janjust

I'd try it first with the "regular" route script, i.e. don't use "route-nopull" but simply let openvpn take care of it - failures in the 'route' commands do NOT cause openvpn to abort.

pette_rsson

Thanks again.

As expected you were right.

It works OK now, with this ifconfig-up script:

#!/bin/sh
/sbin/ifconfig $dev $ifconfig_local netmask $ifconfig_netmask mtu 1500 broadcast $ifconfig_broadcast

Thank you