OVPN connects via UDPv6 if hostname is used, UDPv4 if IP used

ahx-fos

Hi -

My cellphone provider is T-Mobile US. TMO appears to use a sole IPv6 network, which mimics IPv4 to the local OS. Since the most recent iOS OVPN app update, I am experiencing connectivity issues.

If I attempt to connect to my OpenVPN server via a hostname, I connect using UDP6 and my connection is like treacle. It's unusuable.
However, if I change my .ovpn file to connect via my (dynamic) IP, the app connects via UDP4 and everything flows as expected.

WTF is going on? Why am I being forced to use IPv6 if a hostname is used? I appreciate why it does this from a network perspective (ie, TMO using ipv6) but surely I should have the choice as to whether I connect via IPv4 or IPv6?

Currently, OpenVPN is *BROKEN* for T-Mobile USA (LTE) users until they change their hostname to an IP to force an IPv4 connection.

ahx-fos

How do I raise this with the OpenVPN connect developers please? This is a critical issue and needs fixing in their next release.

TinCanTech

If you have an IPv4 IP address for your server then it sounds like you have setup your DDNS solution badly.

ahx-fos

TinCanTech wroteIf you have an IPv4 IP address for your server then it sounds like you have setup your DDNS solution badly.

You have no idea what you are talking about.

int3nt

ahx-fos wroteWTF is going on?

:? :lol:

ahx-fos

int3nt wrote
ahx-fos wroteWTF is going on?
:? :lol:

You, also, clearly have no idea of the problem.

ahx-fos

Here's a further discussion of this issue with other users being affected: https://www.reddit.com/r/tmobile/comments/4pva0t/tmo_ipv6_openvpn/

TinCanTech

Maybe you should have lead with that ..

Or even better ..
done your own research and read the work done by OpenVPN Devs to address the problem:
(referenced in your own link and clearly not read by you)
http://community.openvpn.net/openvpn/ticket/614

ahx-fos wroteYou have no idea what you are talking about

And you are such an expert ? Bad start .. I'm done with this .. ciao

disqualified

ahx-fos wroteWTF is going on?

ahx-fos wroteYou, also, clearly have no idea of the problem.

TinCanTech wroteBad start .. I'm done with this .. ciao

For future ref this may help:
http://catb.org/~esr/faqs/smart-questions.html

debbie10t

To quote from the openvpn bug trac:

TinCanTech wrotehttp://community.openvpn.net/openvpn/ticket/614

cron2 wroteAs there is not much we can do about Apple, but we at least have multiple documented workarounds for their VPN weirdness, I think I'll close this ticket now. (There is a new iOS version coming, so if someone want to test variants on this, please add to the ticket what works and what doesn't)

Please add relevant details to the trac ticket.

ahx-fos

TinCanTech wroteMaybe you should have lead with that ..

Or even better ..
done your own research and read the work done by OpenVPN Devs to address the problem:
(referenced in your own link and clearly not read by you)
http://community.openvpn.net/openvpn/ticket/614

ahx-fos wroteYou have no idea what you are talking about
And you are such an expert ? Bad start .. I'm done with this .. ciao

I'm fully aware of that 'fix'. It still has no relation to the issue at hand. There is NO IPv6 network running on the OVPN server in question. The bug report you cite is not relevant in this case.

TinCanTech

ahx-fos wroteI'm fully aware of that 'fix'.

TinCanTech wroteMaybe you should have lead with that ..

ahx-fos wroteThere is NO IPv6 network running

ahx-fos wroteI connect using UDP6 and my connection is like treacle

ahx-fos wroteThe bug report you cite is not relevant in this case.

I fail to see how blaming openvpn for your network fail is relevant .. caio

ahx-fos

TinCanTech wrote
ahx-fos wroteI'm fully aware of that 'fix'.
TinCanTech wroteMaybe you should have lead with that ..
ahx-fos wroteThere is NO IPv6 network running
ahx-fos wroteI connect using UDP6 and my connection is like treacle
ahx-fos wroteThe bug report you cite is not relevant in this case.
I fail to see how blaming openvpn for your network fail is relevant .. caio

For _my_ network fail? Last time I checked I didn't run TMUS's network.

Regardless, my point is still valid. It's erroneous for OpenVPN Connect to automatically choose ipv6 connectivity despite the issues it still raises (as referenced in the bug cited previous). There should be an option to force the connection to ipv(4|6).

TinCanTech

ahx-fos wrote There should be an option to force the connection to ipv(4|6).

There is.

The manual wrote proto indicates the protocol to use when connecting with the remote, and may be "tcp" or "udp".

For forcing IPv4 or IPv6 connection suffix tcp or udp with 4/6 like udp4/udp6/tcp4/tcp6.

It is not very well documented but it is an option you can try.

oat_bondmen

Thanks for the input.

However, the fix for this is to force T-Mobile to use an ipv4 profile using a custom carrier configuration within Apple Configurator. Once a user does this, ip4 is used again, fixing the brokenness with OpenVPN and T-Mobile ip6.

TinCanTech

oat_bondmen wrote the fix for this is to force T-Mobile to use an ipv4 profile using a custom carrier configuration within Apple Configurator

So nothing to do with openvpn .. good to know.