kex_exchange_identification: Connection closed by remote host

[dongdongbh]

My git(hub) works fine before, but suddenly it not work.
When I type git pull origin master, it shows

kex_exchange_identification: Connection closed by remote host
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

I have configed key, and it works before. My network works fine. ping github.com also works.
Here is the debug message

ssh -vT git@github.com
OpenSSH_8.2p1 Ubuntu-4ubuntu0.5, OpenSSL 1.1.1f  31 Mar 2020
debug1: Reading configuration data /home/dd/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: include /etc/ssh/ssh_config.d/*.conf matched no files
debug1: /etc/ssh/ssh_config line 21: Applying options for *
debug1: Connecting to github.com [20.205.243.166] port 22.
debug1: Connection established.
debug1: identity file /home/dd/.ssh/id_rsa type 0
debug1: identity file /home/dd/.ssh/id_rsa-cert type -1
debug1: identity file /home/dd/.ssh/id_dsa type -1
debug1: identity file /home/dd/.ssh/id_dsa-cert type -1
debug1: identity file /home/dd/.ssh/id_ecdsa type -1
debug1: identity file /home/dd/.ssh/id_ecdsa-cert type -1
debug1: identity file /home/dd/.ssh/id_ecdsa_sk type -1
debug1: identity file /home/dd/.ssh/id_ecdsa_sk-cert type -1
debug1: identity file /home/dd/.ssh/id_ed25519 type -1
debug1: identity file /home/dd/.ssh/id_ed25519-cert type -1
debug1: identity file /home/dd/.ssh/id_ed25519_sk type -1
debug1: identity file /home/dd/.ssh/id_ed25519_sk-cert type -1
debug1: identity file /home/dd/.ssh/id_xmss type -1
debug1: identity file /home/dd/.ssh/id_xmss-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_8.2p1 Ubuntu-4ubuntu0.5
kex_exchange_identification: Connection closed by remote host

git remote -v
origin  git@github.com:dongdongbh/dotfiles.git (fetch)
origin  git@github.com:dongdongbh/dotfiles.git (push)

[airtower-luna]

The SSH output looks like you don't have any keys available for authentication. Do you have SSH-Agent running, and the right key pair loaded into it?

[xc2f]

I encountered the same problem 3 hours ago, unable to push the code to github, it showed no permission, but it was still able to push normally just yesterday. After I generate a new ssh key locally and add it to the github ssh configuration, this problem still exists.
After about five or six minutes, I tried to push again, and the push was successful.

A strange thing happened to me the other day when I was syncing code on another computer. The remote branch is one commit ahead of the local branch, but when I execute git pull or git fetch / rebase locally, it shows Already up to date.. Finally, I deleted the local project and re-pulled the remote code to solve the problem.

[LeisureLinux]

I still have the same issue here in Shanghai. git pull/push through proxy though.
But apparently, since it is through ssh protocol, then the http.proxy setup should not affect.

[dongdongbh]

I have sshd daemon running. I didn't make any change, and now it works, so strange~

[LeisureLinux]

I guess I found the root cause, and had a work around by adding a line in my /etc/hosts Linux Desktop.
pick an IP address from git section in https://api.github.com/meta

❯ grep github /etc/hosts
20.201.28.152 github.com

my original resolving github.com has address 20.205.243.166, is not working.

Unfortunately, no service outage reported in githubstatus.com page.

[LeisureLinux]

Just after a working git pull, and re-run git pull again, found same issue happened on the new IP.
So this workaround won't work, since it is a server side issue.

[xuthus5]

I guess I found the root cause, and had a work around by adding a line in my /etc/hosts Linux Desktop. pick an IP address from git section in https://api.github.com/meta

❯ grep github /etc/hosts 20.201.28.152 github.com

my original resolving github.com has address 20.205.243.166, is not working.

Unfortunately, no service outage reported in githubstatus.com page.

thank you, good for me.

[1990jtf]

wow~ It works! Thanks a lot!

[cooljacket]

But it cause that when i access github.com in Chrome, the web page cannot display right. Finally i recover the local host dns config, use the following LeisureLinux's solution.

[LeisureLinux]

I guess GFW make it.
By checking: https://docs.github.com/en/authentication/troubleshooting-ssh/using-ssh-over-the-https-port
which I followed the ~/.ssh/config added the port 443.
and use command like: "proxychains -q git pull", it is working now.

Here is what is working now through https, and through proxy:

❯ proxychains -q ssh -T git@github.com
The authenticity of host '[ssh.github.com]:443 ([20.205.243.160]:443)' can't be established.
ED25519 key fingerprint is SHA256:+DiY3wvvV6TuJJhbpZisF/zLDA0zPMSvHdkr4UvCOqU.
This key is not known by any other names
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added '[ssh.github.com]:443' (ED25519) to the list of known hosts.
Hi LeisureLinux! You've successfully authenticated, but GitHub does not provide shell access.

[charlesMYoung]

it's working ~~~. nice

[stupidchen]

Cool! It works for me. Thanks!

[HoganBright]

Thank you so much!
2024.05.13 Mon 12:45 from China

[VanillaChelle]

It doesn't work for me by changing ssh to https. I met the same kex_exchange_identification: Connection closed by remote host issue with github ip 20.205.243.166, both in Windows and Mac. Changing ip address resolves this issue. Really appreciate it!

[wangy325]

Thx a lot! works for me.

[dongdongbh]

Because many people in China encounter this problem, seems it's related to network. I reopen this issue. More solution and feedback are welcome.

[LeslieLeung]

Try ssh-keyscan github.com >> ~/.ssh/known_hosts. Works for me.

Found on this post

[airtower-luna]

Never do this, especially not if you know or suspect the government is behind the problem. ⚠️

It means you accept whatever keys the server offers, allowing them to intercept your connection. If there's a problem with the public keys of the server, check if the fingerprint you're seeing is one of the published ones. Same for any other SSH server.

[LeslieLeung]

Thanks for the notice. If anyone did the above, just use ssh-keygen -R github.com to undo it.

P.S. I've checked my known_hosts, the fingerprints are identical to the published ones. Maybe whoever's doing this is not clever/malicious enough to do this.

[AffordCK]

It works for me, thanks!

[ChrisVicky]

Same here in Tianjin, and it's resolved by executing the following command, found here.

ssh -T -p 443 git@ssh.github.com

It seems that something, related to ssh identification or Github ip resolution, has been changed during the execution.

[neufeng]

Very good! Works for me too! I'm in ShangHai! Thanks a lot!

[berrytsukiii]

thx！

[Angeladadd]

Thanks! Works for me along with closing VPN.

[zhaziqwe]

thank you， it really works

[swahpy]

this works for me. Together with adding IP to /etc/hosts file by checking https://dnschecker.org/#A/ssh.github.com. Thanks a lot!

[Seraphli]

Adding this to ~/.ssh/config solves my problem

Host github.com
  Hostname 20.200.245.248
  Port 443

I use South Korea IP.
https://dnschecker.org/#A/ssh.github.com

[yiwenup]

thx!

[y0unghe]

It worked. Thanks!

[kelinkong]

Thanks!

[bqdcc]

Thanks!

[chenyang-zheng]

Life saver, really appreciate it!

[leeeezp]

I have the same problem. It will be normal when I don't use clash.

[iDestin]

I am in Beijing and recently discovered that SSH is not working properly, but I have not found a solution yet

[spianmo]

Enabling SSH connections over HTTPS can solve this problem
If you are able to SSH into git@ssh.github.com over port 443, you can override your SSH settings to force any connection to GitHub.com to run through that server and port.

To set this in your SSH configuration file, edit the file at ~/.ssh/config, and add this section:

Host github.com
    Hostname ssh.github.com
    Port 443
    User git

You can test that this works by connecting once more to GitHub.com:

$ ssh -T git@github.com

Hi USERNAME! You've successfully authenticated, but GitHub does not
provide shell access.

[Mrhs121]

万分感谢！！！

[wangxdmm]

You save my life....

[xxxxinc]

好使的！

[wa008]

works for me

[VictorChow]

GREAT JOB!!!

[zachx121]

try 'ssh-agent && ssh-add ~/.ssh/id_rsa'

[ning2510]

This works for me, thx

[Falasool]

If you use Proxy client like ClashX, please close the "Enhanced Mode" and try again.

[Div1to]

This works for me, thx

[crazy-dadong]

This works for me, thx

[cheung-chifung]

This works for me, thx

[iFTY-R]

This works for me, thx

[Elon-Lee]

Becuase of this problem , check your proxy config . Just like clashx shadowsocks etc ...

[ccsuper1024]

sometimes,Maybe ,we should check our .ssh/ , the public key's and private key's file name.it must start with id_rsa. do not start with anyelse word. I modify the filename ,then ,everything go correct

[mark-wang-beep]

I just closed my ClashX, and then problem solved

[changbindu]

Check the solution here.
https://stackoverflow.com/questions/10127818/ssh-exchange-identification-connection-closed-by-remote-host-under-git-bash

[philipjoep]

This is literally the only thing that worked for me. I'm running a Linux VM on Windows. I unplugged my LAN cable, switched to Wifi, and suddenly I was able to connect to github again. Then after switching back to LAN, it all worked.

Now, I did also update my .ssh/config file and cleared out my known_hosts file before these steps, but they didn't have any affect. I did leave the config file the same.

Host github.com
    Hostname ssh.github.com
    Port 443
    User git

[treblam]

I just closed openclash in my openwrt router, and it works.

[Marerc]

Then how can you access github.com?

[treblam]

github is not blocked in China, but it’s very slow without using proxy.

[arko-svmx]

Make sure if you are using any client connector app like Zscaler, turn its internet security off. It solved every problem for me.

[queenofcorgis]

Given the popularity of this discussion and the quality of information shared, we want to make sure others can easily find it so we’ve reopened this discussion for better discoverability for our members.

[thesilentpsycho]

my org vpn was off. please check

[githika99]

I added this to ~/.ssh/config and it finally worked! I think the hostname is what makes it work.
Host github.com
HostName ssh.github.com
User git
Port 443

Source: https://stackoverflow.com/questions/10127818/ssh-exchange-identification-connection-closed-by-remote-host-under-git-bash

[gospodnetic]

Adding Port 443 and changing HostName to HostName ssh.github.com worked for me! I have user set to my username.

[Narrator]

Hi 👋

I'm an engineer from the AWS Amplify service - Our customers use GitHub to connect their applications to Amplify and we offer a CI/CD workflow where we clone the customer's repository to allow customers to run their build commands.

Since 09/11, our customers have been intermittently observing this issue:

 kex_exchange_identification: Connection closed by remote host
 Connection closed by 20.205.243.166 port 22
 fatal: Could not read from remote repository.
 Please make sure you have the correct access rights
 and the repository exists.

The fact that these failures are intermittent is what is concerning to us. Nothing has changed in the build containers we provision for our customers - The SSH settings are the same as they always were.

We run ssh-keyscan github.com and add the host keys to the ~/.ssh/known_hosts file every time before we clone. Our logs show that this call succeeded, but the failure still occurs.

[wangy325]

This article may help: https://docs.github.com/en/authentication/troubleshooting-ssh/using-ssh-over-the-https-port#enabling-ssh-connections-over-https

I encountered same problem on my git suddenly, and fixed it by following the guide.

[devinburnette]

@Narrator we also started experiencing this issue intermittently around that same time. Let me know if you find a solution!

[Narrator]

I created a separate discussion in the General category with Bug label since it looks very much like something changed on GitHub's side on 09/11: https://github.com/orgs/community/discussions/138757

(This discussion is in the New to GitHub category and perhaps that's the reason it's not gaining much traction from the GitHub staff).