kex_exchange_identification: Connection closed by remote host

??? info “Problem environment”

1
- expected environment: unix

Details of the problem / Steps to reproduce the error

Some time when you try to connect to github, you may get this error:

1
kex_exchange_identification: Connection closed by remote host

TLDR

Add this to your ~/.ssh/config:

1
Host github.com
2
  Hostname 20.200.245.248
3
  Port 443

What I’ve done before the problem is solved (don’t know which one worked):

Close clash for windows
cancel http_proxy and other proxy ports in shell config file (config.fish) and ~/.gitconfig
delete all content in ~/.ssh/known_hosts
ref: https://github.com/orgs/community/discussions/55269, use ssh -Tv -p 443 [email protected], or add this to ~/.ssh/config:

1
Host github.com
2
  Hostname 20.200.245.248
3
  Port 443

verified on 24/5/28, for a new user on Ubuntu, adding this content to config is useful. verified on 24/7/24, worked for wsl when suddenly can’t connect git by cli.

Post test

reopen clash for windows: still ok to ssh
git clone: ok
git pull and push: ok

24.9.27

windows 上和 wsl2 中无法访问阿里云服务器 ssh
solve: 关闭了 Clash Verge 的服务模式（未关闭 tun）
solve2: 开启服务模式 + TUN 并选择直连也可以。这台机子如果不开 TUN, wsl2 的网速异常龟速，即使 win 内的网速正常。