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What causes a connection reset after retransmission and TCP window update?

asked 2018-04-24 17:51:16 +0000

valya gravatar image

I am receiving a webhook from an API with a Jetty server, but connection is reset. What causes that? And what can I do to prevent that?

I am new to this low level stuff and will appreciate your assistance very much.

No.     Time               Source                Destination           Protocol Length Info
  1 16:49:49,666404    104.247.212.130       192.168.1.2           TCP      74     45886 → 443 [SYN] Seq=0 Win=29200 Len=0 MSS=1460 SACK_PERM=1 TSval=2479079241 TSecr=0 WS=128
  2 16:49:49,666566    192.168.1.2           104.247.212.130       TCP      74     443 → 45886 [SYN, ACK] Seq=0 Ack=1 Win=8192 Len=0 MSS=1460 WS=256 SACK_PERM=1 TSval=404273967 TSecr=2479079241
  3 16:49:49,872081    104.247.212.130       192.168.1.2           TCP      66     45886 → 443 [ACK] Seq=1 Ack=1 Win=29312 Len=0 TSval=2479079446 TSecr=404273967
  4 16:49:49,872372    104.247.212.130       192.168.1.2           TLSv1.2  335    Client Hello
  5 16:49:49,922257    192.168.1.2           104.247.212.130       TCP      66     443 → 45886 [ACK] Seq=1 Ack=270 Win=66560 Len=0 TSval=404274223 TSecr=2479079447
  6 16:49:49,933151    192.168.1.2           104.247.212.130       TLSv1.2  3744   Server Hello, Certificate, Server Key Exchange, Server Hello Done
  7 16:49:50,135955    104.247.212.130       192.168.1.2           TCP      78     [TCP Window Update] 45886 → 443 [ACK] Seq=270 Ack=1 Win=30848 Len=0 TSval=2479079711 TSecr=404274223 SLE=2897 SRE=3679
  8 16:49:50,345548    192.168.1.2           104.247.212.130       TCP      1514   [TCP Retransmission] 443 → 45886 [PSH, ACK] Seq=2231 Ack=270 Win=66560 Len=1448 TSval=404274646 TSecr=2479079711
  9 16:49:51,014563    192.168.1.2           104.247.212.130       TCP      1514   [TCP Retransmission] 443 → 45886 [ACK] Seq=1 Ack=270 Win=66560 Len=1448 TSval=404275315 TSecr=2479079711
 10 16:49:52,251300    192.168.1.2           104.247.212.130       TCP      1514   [TCP Retransmission] 443 → 45886 [ACK] Seq=1 Ack=270 Win=66560 Len=1448 TSval=404276552 TSecr=2479079711
 11 16:49:54,723267    192.168.1.2           104.247.212.130       TCP      590    [TCP Retransmission] 443 → 45886 [ACK] Seq=1 Ack=270 Win=66560 Len=524 TSval=404279024 TSecr=2479079711
 12 16:49:54,879025    104.247.212.130       192.168.1.2           TCP      78     45886 → 443 [RST, ACK] Seq=270 Ack=1 Win=30848 Len=0 TSval=0 TSecr=404274223 SLE=2897 SRE=3679
 13 16:49:54,931866    104.247.212.130       192.168.1.2           TCP      60     45886 → 443 [RST] Seq=270 Win=0 Len=0
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answered 2018-04-25 04:42:23 +0000

mrEEde gravatar image

The connection gets reset by the Windows server after having exhausted its re-transmission retries trying to get the full size 1448 bytes segments to the Linux client.
This is most probably due to the MTU size available along the route being smaller than 1500, which is what both sides have defined.
Assuming have control over the server you could manually reduce the MTU size to let's say 1400 to circumvent this problem.
From https://answers.microsoft.com/.../how-do-i-change-the-mtu-setting-in-windows-7/ image description

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Asked: 2018-04-24 17:51:16 +0000

Seen: 7,141 times

Last updated: Apr 25 '18