Linux tips: Troubleshoot SSH connection latency issues

Troubleshoot SSH connections waiting a few seconds

Peacetime when we connect ssh, often have to wait 5 seconds or longer, to connect, because it is a virtual machine, the host through Vmnet8 and virtual machine is the same network segment, there is no delay problem, that must be virtual machine sshd configuration problem. Annoyed for a long time, suddenly any classmate mentioned sshd_config a parameter configuration Usedns can solve this problem, online check information, sure enough to have an impact, explanation is this: SSH although with IP connection, but SSH connection, the server will check the IP PTR record, Because the PTR record is not found and the last error is returned to respond to the client's connection, the client is waiting until the usedns is shut down to resolve the problem. 1. Back up and modify/etc/ssh/sshd_config, change Usedns to No

#ShowPatchLevel Nousedns No #PidFile/var/run/sshd.pid

2. Restart the SSHD service

/etc/init.d/sshd restart

Over

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Linux tips: Troubleshoot SSH connection latency issues