Hi, Can anyone help me to understand this captures?
client 72.189.226.91 server 192.168.78.118 port 8086
Client report random connection problem on connect to server port 8086. I attach the anon captures
For example (one error time):
- Captures at Client side (client_side_anon.pcapng) 2020-11-11 12:39:49,591869 72.189.226.91 192.168.78.118 TCP 74 43188 → 8086 [SYN] Seq=0 Win=14600 Len=0 MSS=1460 SACK_PERM=1 TSval=739647657 TSecr=0 WS=64
The server doesn't response to this SYN with an ACK (really yes but it does not receive it, see below the capture on the server)
Client request again 2020-11-11 12:39:52,595107 72.189.226.91 192.168.78.118 TCP 74 [TCP Retransmission] 43188 → 8086 [SYN] Seq=0 Win=14600 Len=0 MSS=1460 SACK_PERM=1 TSval=739648408 TSecr=0 WS=64 ... at this point fail.
- Caputres at Server side (server_side_anon.pcacpng) The SYNC is received by the server
2020-11-11 12:39:49,599532 72.189.226.91 192.168.78.118 TCP 74 43188 → 8086 [SYN] Seq=0 Win=14600 Len=0 MSS=1460 SACK_PERM=1 TSval=739647657 TSecr=0 WS=64 and it response with ACK
2020-11-11 12:39:49,599568 192.168.78.118 72.189.226.91 TCP 66 8086 → 43188 [ACK] Seq=1 Ack=2413873066 Win=249 Len=0 TSval=190156218 TSecr=697151199
But this ACK is never seen at client side
Why this ACK i not received by the client side and it requet again? and the server resends it ... and so on. TCP Retransmission Where can the problem be here?
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