ssh GitHub 卡在认证步，如何解决？

[coderfox]

$ ssh -T -vvv -i ~/.ssh/id_rsa [e-mail]
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。

[lcdtyph]

挂代理试试吧~

[coderfox]

发现问题恰恰出在代理服务器上，关掉用的 VRouter 以后就没问题了。终于找到一份资料，说是 MTU 设置太大……
https://stackoverflow.com/questions/24052623/ssh-connection-established-but-stuck
去给作者报 Issue 了。