解决：-oKexAlgorithms=+diffie-hellman-group1-sha1
问题：Unable to negotiate with 192.168.xx.xx port 22: no matching host key type found. Their offer: ssh-dss
解决：-oHostKeyAlgorithms=+ssh-dss
问题：Unable to negotiate with 192.168.xx.xx port 22: no matching cipher found. Their offer: 3des-cbc
解决：-oCiphers=+3des-cbc
最后命令是这样的：
ssh -oKexAlgorithms=+diffie-hellman-group1-sha1 -oHostKeyAlgorithms=+ssh-dss -oCiphers=+3des-cbc user@192.168.xx.xx
登录strongswan测试环境中的主机会出现
$ ssh root@192.168.0.1
Unable to negotiate with 192.168.0.1 port 22: no matching cipher found. Their offer: arcfour
意思是本地默认不支持arcfour算法，
用如下方法就可以访问：
ssh -oCiphers=arcfour root@192.168.0.1
