Datagroup.UA and openvpn (proto UDP)?

Question

openvpn

Lord! We are looking for users of providers using Datagroup (Ukraine) and OpenVPN channels.
Faced with a mysterious problem today, previously configured and working like a clock, OpenVPN clients began to “fail” - either the connection will break, or something else. OpenVPN is configured to work over UDP.
From 100% reproducible:
- when connecting to the server through a tunnel, SSH sessions are hung up in PuTTY when trying to start top, mc or execute "ls -l /" or "ls -l /bin"
- mail does not go through pop3
When translating the server and clients on TCP the problem disappears.
It's funny, but if the client is not connected via datagroup, then there are no problems with UDP. I received several confirmations from Kyiv and Zhytomyr (dks.com.ua drives traffic through datagroup channels).
Actually, I'm looking to confirm or refute the hypothesis that the datagroup today began to do evil with UDP traffic.
Thanks in advance to everyone who, using datagroup and openvpn over UDP, will share relevant information in the form of “confirm. I also have glitches / I don’t confirm, everything is OK with me. ”

Answer 1

I don't know anything about Datagroup.UA, but try reducing the MTU in the OpenVPN config. For example:
tun-mtu 1300

Answer 2

UDP is faster, but it has a rake. It doesn't establish a connection. Hence the conclusion: it is reasonable to use UDP only in proven, reliable networks, for example, in LAN inside the office. In bad networks, packets are lost, and it turns out, including what happened to you. Although, of course, the legs of the problems described by you and me grow from slightly different places, the result is the same.