Connection SSH response is slow, card, delay

1. Turn off DNS reverse resolution
In Linux, the default is to turn on SSH's reverse DNS resolution, which consumes a lot of time and therefore needs to be shut down.
# Vi/etc/ssh/sshd_config
Usedns=no

In the configuration file, although Usedns Yes is commented, the default switch is Yes

2. Close the GSS certification on the server
There are a lot of possible problems with authentication gssapi-with-mic, so shutting down GSS authentication can improve the SSH connection speed.

# Vi/etc/ssh/sshd_config
Gssapiauthentication No

Note: After the change, remember to restart the SSHD service
# Service Sshd Restart

Connection SSH response is slow, card, delay