How to fix Write failed: Broken pipe in SSH

The ServerAliveInterval setting tells your SSH client to send keep-alive packets to the server at regular intervals, preventing idle timeout disconnections.

For a single connection:

ssh -o ServerAliveInterval=60 user@host

For all future connections, edit your ~/.ssh/config file:

Host *
    ServerAliveInterval 60
    ServerAliveCountMax 120

This tells SSH to send a keep-alive packet every 60 seconds, and disconnect only after 120 failed attempts (120 minutes of no response).

TCPKeepAlive works at the TCP layer to prevent connection drops before SSH keep-alives kick in.

Add to ~/.ssh/config:

Host *
    TCPKeepAlive yes
    ServerAliveInterval 60
    ServerAliveCountMax 120

TCPKeepAlive yes is usually the default, but explicitly setting it ensures TCP-level keep-alives are enabled.

If the broken pipe happens despite client-side settings, or if you administer the SSH server, configure server-side keep-alives.

Edit /etc/ssh/sshd_config on the server:

ClientAliveInterval 120
ClientAliveCountMax 720

This tells the SSH daemon to:
- Send a keep-alive packet every 120 seconds
- Only drop the connection after 720 failed attempts (about 24 hours)

After editing, restart the SSH daemon:

sudo systemctl restart sshd
# or on older systems:
sudo service ssh restart

Verify your settings are working by leaving an SSH session idle and checking it doesn't disconnect.

Check client configuration:

ssh -G user@host | grep -i alive

Check server configuration (requires server access):

sudo grep -i ClientAlive /etc/ssh/sshd_config

Connect and wait 5+ minutes without activity. If it disconnects, proceed to the next step.

If the issue persists despite proper SSH keep-alive settings, the problem may be an intermediary network device (firewall, NAT, proxy, or ISP).

Diagnose with verbose output:

ssh -vvv user@host

Watch the logs for timeout messages. If the disconnect happens at a consistent interval (e.g., every 15 minutes), it's likely a firewall or ISP setting.

Solutions:
- Contact your ISP or network administrator about idle connection timeouts
- Adjust firewall rules to increase timeout thresholds
- For cloud environments (AWS, Azure, GCP), check security group rules and network ACLs
- Consider using an SSH jumphost or bastion with longer timeout settings

If keep-alive settings don't solve the problem, use tmux or screen to maintain a persistent session that survives SSH disconnects.

Using tmux:

# Create a new session
tmux new-session -s work

# Detach (keeps running)
Ctrl+B D

# Reconnect later
tmux attach-session -t work

Using screen:

# Create a new session
screen -S work

# Detach (keeps running)
Ctrl+A D

# Reconnect later
screen -r work

With tmux/screen, your session persists on the server even if the SSH connection breaks.