M
Matthias R. Wiora
Hi all,
I have a very strange Network behaviour with my two Windows Server 2016 Hyper-V Hosts (Server A and B)....
I've realized the issues as I was trying to copy a 200gb disk-file from one host to another - what resulted in a drop to 0 MBits/sec copy speed, which sometimes recovers, sometimes the operation is being interrupted.
iPerf under Windows show nothing special...
iPerf under linux (in a VM) shows some minor losses, but Server B is under active usage (1-10 MBit/s), so Congestion might occur.
[ ID] Interval Transfer Bandwidth Retries CWND
[ 4] 857.00-858.00 sec 108 MBytes 903 Mbits/sec 101 242 KBytes
[ 4] 858.00-859.00 sec 108 MBytes 905 Mbits/sec 38 335 KBytes
[ 4] 859.00-860.00 sec 108 MBytes 910 Mbits/sec 37 407 KBytes
[ 4] 860.00-861.00 sec 106 MBytes 888 Mbits/sec 76 393 KBytes
[ 4] 861.00-862.00 sec 108 MBytes 904 Mbits/sec 75 274 KBytes
[ 4] 862.00-863.00 sec 109 MBytes 912 Mbits/sec 0 441 KBytes
[ 4] 863.00-864.00 sec 109 MBytes 917 Mbits/sec 113 252 KBytes
[ 4] 864.00-865.00 sec 107 MBytes 901 Mbits/sec 38 346 KBytes
[ 4] 865.00-866.00 sec 109 MBytes 915 Mbits/sec 75 317 KBytes
[ 4] 866.00-867.00 sec 109 MBytes 916 Mbits/sec 37 335 KBytes
The number of link down events does not change on the switch...
The error occurs mostly between 300 and 1000 seconds after start - but sometimes there happens exactly nothing. Everything works as expected
A ping from one side to the other works perfectly.
Already tried:
- Wireshark - nothing special...
- Latest Network driver (2019/12)
- Latest Windows Updates installed (up to February 2020)
- enabled NIC-Teaming on Server B
- Disabled Send Large Offloading IPv4 on sender (and later on receiver)
- Disabled Send Large Offloading IPv6 on sender (and later on receiver)
- Disabled IPv6 on sender (I am using it actively in this network)
Hardware-Side:
- Changed temporarily to another switch
- Changed network cables
The hardware: HP Gen8 Microserver (Server A), HP Gen8 DL360p (Server B), Ubiquiti Unifi Switch 24 Port
Did anyone have had a similar issue in the past? And how did you solve it?
Cheers,
matthias
Continue reading...
I have a very strange Network behaviour with my two Windows Server 2016 Hyper-V Hosts (Server A and B)....
I've realized the issues as I was trying to copy a 200gb disk-file from one host to another - what resulted in a drop to 0 MBits/sec copy speed, which sometimes recovers, sometimes the operation is being interrupted.
iPerf under Windows show nothing special...
iPerf under linux (in a VM) shows some minor losses, but Server B is under active usage (1-10 MBit/s), so Congestion might occur.
[ ID] Interval Transfer Bandwidth Retries CWND
[ 4] 857.00-858.00 sec 108 MBytes 903 Mbits/sec 101 242 KBytes
[ 4] 858.00-859.00 sec 108 MBytes 905 Mbits/sec 38 335 KBytes
[ 4] 859.00-860.00 sec 108 MBytes 910 Mbits/sec 37 407 KBytes
[ 4] 860.00-861.00 sec 106 MBytes 888 Mbits/sec 76 393 KBytes
[ 4] 861.00-862.00 sec 108 MBytes 904 Mbits/sec 75 274 KBytes
[ 4] 862.00-863.00 sec 109 MBytes 912 Mbits/sec 0 441 KBytes
[ 4] 863.00-864.00 sec 109 MBytes 917 Mbits/sec 113 252 KBytes
[ 4] 864.00-865.00 sec 107 MBytes 901 Mbits/sec 38 346 KBytes
[ 4] 865.00-866.00 sec 109 MBytes 915 Mbits/sec 75 317 KBytes
[ 4] 866.00-867.00 sec 109 MBytes 916 Mbits/sec 37 335 KBytes
The number of link down events does not change on the switch...
The error occurs mostly between 300 and 1000 seconds after start - but sometimes there happens exactly nothing. Everything works as expected
A ping from one side to the other works perfectly.
Already tried:
- Wireshark - nothing special...
- Latest Network driver (2019/12)
- Latest Windows Updates installed (up to February 2020)
- enabled NIC-Teaming on Server B
- Disabled Send Large Offloading IPv4 on sender (and later on receiver)
- Disabled Send Large Offloading IPv6 on sender (and later on receiver)
- Disabled IPv6 on sender (I am using it actively in this network)
Hardware-Side:
- Changed temporarily to another switch
- Changed network cables
The hardware: HP Gen8 Microserver (Server A), HP Gen8 DL360p (Server B), Ubiquiti Unifi Switch 24 Port
Did anyone have had a similar issue in the past? And how did you solve it?
Cheers,
matthias
Continue reading...