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Hi,
got some mysterious network problems, a connection between two archlinux machienes over several switches keeps loosing packets or at least wireshark says:
TCP Previous Segment lost
TCP Retransmission
but only if i use scp, no errors with https
datar ates are ~6mybte/s for scp and 11,5mbyte/s for https
both systems loads are below 0.5
any idea what that could be?
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does ifconfig output show any errors, dropped, overruns, or collisions?
"Be conservative in what you send; be liberal in what you accept." -- Postel's Law
"tacos" -- Cactus' Law
"t̥͍͎̪̪͗a̴̻̩͈͚ͨc̠o̩̙͈ͫͅs͙͎̙͊ ͔͇̫̜t͎̳̀a̜̞̗ͩc̗͍͚o̲̯̿s̖̣̤̙͌ ̖̜̈ț̰̫͓ạ̪͖̳c̲͎͕̰̯̃̈o͉ͅs̪ͪ ̜̻̖̜͕" -- -̖͚̫̙̓-̺̠͇ͤ̃ ̜̪̜ͯZ͔̗̭̞ͪA̝͈̙͖̩L͉̠̺͓G̙̞̦͖O̳̗͍
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no, ifconfig output looks fine.
its probably a switch somewhere along the path.
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Is it the infamous TCP window scaling problem? If you haven't tried it already, issue
echo 0 > /proc/sys/net/ipv4/tcp_window_scaling
and see if it gets any better. Alternatively, add the line
net.ipv4.tcp_window_scaling = 0
to the file /etc/sysctl.conf and issue sysctl -p
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ah, didnt know about that. but didnt help.
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Is the MTU for all networked devices set correctly? Have you checked ifconfig's output for errors on both sides?
:?
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Yes, no errors on both sides.
havent played around with the MTU. ifconfig reports MTU as 1500
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Can you post a full dump? (.pcap file). Please make sure it only contains your scp traffic and no other traffic.
:?
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