ssh-licco: Skill for Claude Code

SSH MCP Troubleshooting Guide

Quick Diagnostics

Check SSH Connection

ping -c 4 43.143.207.242
nc -zv 43.143.207.242 22
telnet 43.143.207.242 22

Check Server Status

systemctl status sshd
systemctl status firewalld
iptables -L -n
df -h
free -m
uptime

Common Issues

1. Connection Timeout

Symptoms:

• "Connection timed out"
• "No route to host"

Solutions:

1. Check server IP is correct
2. Check server is running
3. Check firewall allows SSH (port 22)
4. Check server has network connectivity
5. Try with longer timeout: timeout=120

MCP Example:

连接 SSH，host=43.143.207.242, username=root, password=xxx, timeout=120

2. Authentication Failed

Symptoms:

• "Authentication failed"
• "Permission denied"

Solutions:

1. Verify username is correct
2. Verify password is correct
3. Check SSH config: PasswordAuthentication yes
4. Check user exists on server
5. Check user has shell access: grep username /etc/passwd

Server Commands:

sudo grep "PasswordAuthentication" /etc/ssh/sshd_config
sudo systemctl restart sshd

3. Error Reading SSH Protocol Banner

Symptoms:

• "Error reading SSH protocol banner"
• "Connection closed by remote host"

Solutions:

1. SSH service may be hung - restart it:

   sudo systemctl restart sshd
   

2. Check SSH service status:

   sudo systemctl status sshd
   sudo journalctl -u sshd -n 50
   

3. Check server load:

   uptime
   top
   

4. Check SSH port is responding:

   nc -zv hostname 22
   

4. Host Key Verification Failed

Symptoms:

• "Host key verification failed"
• "Known hosts file error"

Solutions:

1. Remove old host key:

   ssh-keygen -R hostname
   

2. Or use accept_new_host_key=true in ssh_connect (testing only):

   连接 SSH，host=xxx, accept_new_host_key=true
   

3. Or disable strict checking (not recommended for production):

   连接 SSH，host=xxx, strict_host_key_checking=false