OpenVPN server default topology change?

[oldgringo]

It seems that in the latest version of openvpn there is not net30 topology as a default for a server but topology subnet. I had to add "topology net30" explicitly to the custom config section otherwise my clients get wrong tunnel addresses (masks).

 

[john9527]

Yes, that is a change that Merlin made (and I picked up in my fork). Sounds as if you should consider updating your VPN clients or continue to use your override (should probably do it via a postconf script).

From the OpenVPN website....
Subnet topology is the current recommended topology; it is not the default as of OpenVPN 2.3 for reasons of backwards-compatibility with 2.0.9-era configs. It is safe and recommended to use subnet topology when no old/outdated clients exist that are running OpenVPN 2.0.9 under Windows.

 

[oldgringo]

It's not such a big problem for me, it's about to add 2 rows to the config on a server side. But it's a bit strange to hear that it's not the default as a reason for backwards compatibility. Until previous version if there was no topology row in server setup it supposed net30 as a default and all clients the same. Now, when I change a server to the latest version (without change of config), all the clients still suppose they use net30 (until I've upgrade them too) and reject to connect. I don't thing we can talk about backwards compatibility even if it can be achieved easily. It was a change of some default settings and as such should be mentioned at least in the changelog. Otherwise it's difficult to find it from server side because it can be seen only in logs on client side, you know. That's my point of view.