ssh GitHub 卡在认证步，如何解决？

$ ssh -T -vvv -i ~/.ssh/id_rsa [email protected] OpenSSH_7.5p1, LibreSSL 2.5.4 debug1: Reading configuration data /Users/coderfox/.ssh/config debug1: /Users/coderfox/.ssh/config line 1: Applying options for * debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 52: Applying options for * debug2: resolving "github.com" port 22 debug2: ssh_connect_direct: needpriv 0 debug1: Connecting to github.com [192.30.255.112] port 22. debug1: Connection established. debug1: identity file /Users/coderfox/.ssh/id_rsa type 1 debug1: key_load_public: No such file or directory debug1: identity file /Users/coderfox/.ssh/id_rsa-cert type -1 debug1: identity file /Users/coderfox/.ssh/id_rsa type 1 debug1: key_load_public: No such file or directory debug1: identity file /Users/coderfox/.ssh/id_rsa-cert type -1 debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_7.5 

就卡在这里了。但是用 HTTPS 可以推代码，ssh 连我自己的主机也没问题（同一个公私钥对）。

过一段时间以后会提示「 Connection closed by remote host 」。

在网络上搜索了一下，还没发现相似的问题。此问题出现在最近一周。

希望能够得到帮助，谢谢。