I figure out that some DTAG AS3320 networks are blocked by firewalls or by hetzner:

DTAG ip-prefix 84.165.0.0/16 looks blocked

I rechecked with IPs from our vienna datacenter and used other routings, IPs from the range:
80.64.0.0/16 are working at the moment.

Looks like, a not working ddos-protection or other things blocks the connection, even when many

retrys comes from the same sender...

Loosing the connections with excavator is another thing. Eventually there is a problem
with MTU path discovery or packages with an MTU < 1500 are dropped. (pppoe packages uses 1492 MTU, vpn-sessions even less, like 1400)

...and the next thing is, by using excavator, i lost all few minutes the connection and can´t reconnect.
I tryed this since a few hours, and always mining only a few minutes. Restarting and no reconnect

possible. Is the stratum-server at the moment in a continous restarting-situation because of
bugfixxing ?

I been using miningpoolhub with booth miners since few days and i never have such problems :(