Ubuntu 12.04中xshell链接报： Connection closed by foreign host.错误

Ubuntu 12.04中xshell链接报：Read from socket failed: Connection reset by peer 或者 Connection closed by foreign host.错误解决办法：

该问题出现的原因是/etc/ssh目录下的文件的熟悉被修改了，从新修改回原始状态即可：

cd /etc/ssh

sudo chmod 644 ./*

sudo chmod 600 ssh_host_dsa_key

sudo chmod 600 ssh_host_rsa_key

sudo chmod 755 .