Since April connections to Hetzner are often stuck at 150kb/s.
You can easily test by trying wget http://speed.hetzner.de/1GB.bin -4 -O /dev/null multiple times.
It’s like 50/50 chance to get a very slow connection. Just try it 10 times and you’ll see yourself.
--2018-04-13 17:02:14-- http://speed.hetzner.de/1GB.bin
Resolving speed.hetzner.de (speed.hetzner.de)... 88.198.248.254
Connecting to speed.hetzner.de (speed.hetzner.de)|88.198.248.254|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1048576000 (1000M) [application/octet-stream]
Saving to: ‘/dev/null’
/dev/null 0%[ ] 1001K 149KB/s eta 1h 45m
Iperf to hetzner looks like this (when it’s happening):
[ ID] Interval Transfer Bandwidth
[ 5] 0.00-1.00 sec 334 KBytes 2.73 Mbits/sec
[ 5] 1.00-2.00 sec 184 KBytes 1.51 Mbits/sec
[ 5] 2.00-3.00 sec 232 KBytes 1.90 Mbits/sec
[ 5] 3.00-4.00 sec 185 KBytes 1.52 Mbits/sec
[ 5] 4.00-5.00 sec 266 KBytes 2.18 Mbits/sec
[ 5] 5.00-6.00 sec 225 KBytes 1.84 Mbits/sec
[ 5] 6.00-7.00 sec 221 KBytes 1.81 Mbits/sec
[ 5] 7.00-8.00 sec 72.1 KBytes 591 Kbits/sec
[ 5] 8.00-9.00 sec 102 KBytes 834 Kbits/sec
[ 5] 9.00-10.00 sec 163 KBytes 1.33 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bandwidth Retr
[ 5] 0.00-10.00 sec 1.98 MBytes 1.66 Mbits/sec 112 sender
[ 5] 0.00-10.00 sec 1.98 MBytes 1.66 Mbits/sec receiver
Iperf online.net to online.net:
[ 3] 0.0- 2.0 sec 226 MBytes 947 Mbits/sec
[ 3] 2.0- 4.0 sec 224 MBytes 941 Mbits/sec
[ 3] 4.0- 6.0 sec 224 MBytes 938 Mbits/sec
[ 3] 6.0- 8.0 sec 225 MBytes 944 Mbits/sec
[ 3] 8.0-10.0 sec 223 MBytes 937 Mbits/sec
[ 3] 10.0-12.0 sec 224 MBytes 940 Mbits/sec
[ 3] 12.0-14.0 sec 225 MBytes 945 Mbits/sec
[ 3] 14.0-16.0 sec 223 MBytes 935 Mbits/sec
[ 3] 16.0-18.0 sec 225 MBytes 943 Mbits/sec
[ 3] 18.0-20.0 sec 224 MBytes 941 Mbits/sec
[ 3] 0.0-20.0 sec 2.19 GBytes 941 Mbits/sec
It’s not only my server! I asked some friends, who also have servers at online.net and hetzner. They have the same problem. DC2 or DC3 doesn’t matter.
Also the hetzner DC doesn’t matter. The issue persists for 12 days now. Day or nighttime doesn’t matter. It’s 24/7 slow like this.
I don’t want to name my ticketnumber. I filed an issue with a reseller of online.net servers.
I doubt he even forwarded it. He just forwarded me some messages not looking like they were written by online.net staff. Then made a speedtest-cli and said everything is fine 
I don’t want to put my server in rescue mode anymore. It’s just a general issue with the networking at ANY online.net server. You can really test it yourself.
I would be really glad if you can forward this to your network team and make some tests. My routing is via NL-IX, which looks good on the network weathermap.