How to deal with TCP retransmission

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The client accesses the remote server with normal ping latency, but the system opens very slowly. Packet capture on the client shows TCP retransmission. How to determine the specific problem?

Re-transmission may be due to packet loss, or the terminal receiving the message may consider it out of order and not process it. There are too many possible reasons for this phenomenon, and it is necessary to locate the devices and interfaces one by one to see where the loss is occurring, which is very troublesome.

 Just from the perspective of the router/switch, you can adjust the tcp mss of the interface to see if it improves the packet loss issue. You can try adjusting it to 1200, 1000, and 800, and after the adjustment, you need to shut down and then undo the shut on the interface to let tcp renegotiate and take effect.

<Sysname> system-view

[Sysname]int g1/0/3

[Sysname-GigabitEthernet1/0/3] tcp mss 800