Developers

SSH and Git time out on a Mac

SSH and Git need a working TCP connection to the server. A network that blocks port 22, a broken IPv6 path or a proxy can stop them.

Applies to: All current macOS versions with the OpenSSH and Git that macOS or Homebrew installs.Checked: 29 October 2026

Symptoms

  • git push or git clone waits, then shows “Operation timed out”.
  • ssh shows “Connection timed out” on one network but works on another.
  • An SSH session freezes after some idle minutes.
  • HTTPS Git remotes work, but SSH remotes do not.

Likely causes

  • Port 22 is blocked. Some company, hotel and public networks block SSH. GitHub says that firewalls sometimes refuse SSH connections.
  • A broken IPv6 path. The Mac tries IPv6 first. If IPv6 does not work, the connection waits.
  • Idle connections close. A router or firewall can drop a connection that sends no data for some time.
  • A proxy is necessary. HTTPS Git on a company network can need http.proxy or proxy variables.

How to check

  1. Connect with verbose output. The last lines show where the connection stops.

    ssh -vT git@github.com

  2. Test the TCP port alone, with a 5-second timeout.

    nc -vz -G 5 github.com 22

  3. Try IPv4 only. If this works, the IPv6 path is the problem.

    ssh -4 -T git@github.com

  4. Test GitHub's SSH service on port 443.

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

  5. Show Git's proxy setting and your proxy variables.

    git config --get http.proxy
env | grep -i proxy

How to fix it

  1. If port 22 is blocked, use SSH over port 443 for GitHub. Add this block to ~/.ssh/config.

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

  2. If IPv6 fails, use IPv4 for that host. Add AddressFamily inet to its block in ~/.ssh/config.

  3. To keep idle sessions open, send a message every 60 seconds. Add ServerAliveInterval 60 to the host block.

  4. To stop long waits, add ConnectTimeout 10 to the host block.

  5. For HTTPS remotes behind a proxy, set Git's proxy.

    git config --global http.proxy http://proxy.example.com:8080

  6. As a test, use the HTTPS URL of the repository instead of the SSH URL.

With Kilobat

  1. Kilobat's connection check tests IPv4 and IPv6 separately, so a broken IPv6 path gets a clear answer.

    kilobat why github.com

  2. See the open connections of one process.

    kilobat destinations --pid 12345

Questions

Why does ssh -4 work when plain ssh does not?

The Mac tried IPv6 first, and the IPv6 path did not work. With -4, ssh uses IPv4 only.

What does ServerAliveInterval do?

ssh sends a message through the connection after that many seconds without data. The default is 0, which sends none.

Sources

  • GitHub Docs: Using SSH over the HTTPS port
  • ssh(1) and ssh_config(5), man page installed with macOS 27.2
  • nc(1), man page installed with macOS 27.2
  • git-config(1), http.proxy, man page installed with macOS 27.2 (Git 2.56)

Sources checked on 29 October 2026. Man pages are the ones installed with macOS; open one with man <name> in Terminal.