GitHub SSH over Port 443

A Git SSH remote (git@github.com:...) connects to host github.com on port 22 by default. Some networks, often captive-portal or hotel Wi-Fi, block outbound port 22, so the connection never completes and Git fails with a timeout. GitHub also serves SSH on ssh.github.com port 443, the HTTPS port, which is almost never blocked. Pointing github.com at that endpoint in the SSH config fixes it without changing any remote URLs.

The symptom

Push, pull, or ssh -T hangs for a while, then times out. Keys and the repo are fine, the packets just never leave the network.

ssh: connect to host github.com port 22: Connection timed out
fatal: Could not read from remote repository.

Confirm port 22 is blocked

Test the two ports without extra tools using the bash /dev/tcp builtin. If 22 hangs and 443 connects, the network is blocking 22, not GitHub or your keys.

timeout 5 bash -c '</dev/tcp/github.com/22'      && echo "22 open"  || echo "22 blocked"
timeout 5 bash -c '</dev/tcp/ssh.github.com/443' && echo "443 open" || echo "443 blocked"

Route github.com over 443

Add a host block to ~/.ssh/config (create the file if it does not exist). This rewrites the connection: commands still target github.com, but SSH dials ssh.github.com on 443 instead.

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

Only the destination host and port change, from github.com:22 to ssh.github.com:443. The protocol, keys, and authentication are identical, so no remote URLs need editing. The Host github.com alias catches every remote that uses git@github.com.

Verify

Authenticate, then use Git normally.

ssh -T git@github.com   # greets you by username
git push

A successful greeting confirms Git is now reaching GitHub over 443.

See also

• GitHub SSH Authentication for Local and EC2
• Docker and Wi-Fi Subnet Conflict