After reloading the system, GIT push and SSH login to the remote server failed all the time. Before reloading the system, we didn’t find this problem

Later, SSH – V logged in to check the log and found that it was stuck in debug1: SSH2_ MSG_ KEXINIT sent。 Until the last link fails

I checked a lot on the Internet and found that it was because the MTU value was too large

Refer to https://blog.csdn.net/wjciayf/article/details/76916075

http://techbackground.blogspot.com/2013/06/path-mtu-discovery-and-gre.html

Then set the MTU value

The configuration in “hardware” is changed from “automatic” to “manual”, and MTU is set to standard. After that, it’s OK