Client with XP cannot connect with OpenVPN

[viragomann]

I agree with Chris.

Apart from this, Windows XP does not support GCM encryption. This is only supported by OpenVPN 2.4, but that cannot be installed on XP. Also NCP is not supported by OpenVPN versions lower 2.4.
So to connect XP clients to the server you must change the encryption algorithm, e.g. to a CBC version. If you intend to do that, also check "Enable NCP" and select your preferred GCM algorithm from the list below. That enables NCP capable clients to connect with GCM encryption, while elder clients can connect with the algorithm you've selected at "Encryption Algorithm".

[johnpoz]

Going to chime in as well - XP should no longer be viable OS… If you are using it for some legacy something.  It should not have any sort of network access at all..

Viragomann work around should be work - but better is to move away from such an OLD OS that has no support.

[Zyhr]

Ok, thank to all of you.

Yeah, I agree about XP should be retired, but it's not my decision.

I will try viragomann solution and will let you know about as soon as possible.

[johnpoz]

Make it their decision to update their OS then.. Sorry "MY" vpn doesn't work with XP since it is non support OS and security issue.

Update your OS to supported version, or sorry will not be able to connect to "MY" vpn ;)

[jahonix]

^ exactly how I would handle this.
Sometimes people need a hard reminder to change necessary stuff. Now you have the option!

[Zyhr]

I was going to change encryptation but, as you can see on picture attached, it seems to be already as viragomann sujested.

Is this how it should be or I should change anything?

I would like to do that, so they change XP to, at least, Windows 7 but as far as I know, my boss already told they will be able with XP (we're a technical support company)

Again, thanks allf of you for your help.


[viragomann]

Maybe it helps to remove the ncp-ciphers line from the client config.

[Zyhr]

I will try tomorrow then.

Thanks!

[johnpoz]

"my boss already told they will be able with XP"

Well clearly your boss spoke out his ass without knowing anything..  That your boss would say XP is fine is clearly out of touch with IT from every angle…

[Zyhr]

Hi all,

After removing whole line now works.

So, for anyone that may come in the future with the same problem, solutions is remove the following line only in conf file of windows xp clients

ncp-ciphers AES-256-GCM: AES-128-GCM

One more time thanks all of you for your help.

Have a nice day!

[jimp]

If you use the client export package, you can click the option to export one of the old windows installers with the "-xp" suffix, and you can also check the "legacy client" option in the export package when making inline configurations.

But the best thing to do is ditch XP.