Recently, the SSH service connection suddenly appears no matching host key type found. Their offer: SSH DSS there has been no problem before

Possible causes

Openssh service upgrade, encryption algorithm support issues

Be careful of being mined (it has been possible before, but the new one can’t, mainly check the sshd service configuration)

General solution

On the algorithm of sshd

Command line add ssh -oHostKeyAlgorithms=+ssh-dss user@legacyhost
Add HostKeyAlgorithms +ssh-dss to the configuration~/.ssh/config
如下：
Host somehost.example.org
    HostKeyAlgorithms +ssh-dss

Mining problems

The mining company likes to modify the sshd service, as well as some timed tasks, this can be checked with tools, or ssh configuration comparison, find to modify, pay attention to clear the
abnormal processes, clear timing tasks