AWS Ubuntu实例SSH连接超时求助：使用客户提供的IP与.pem连接失败

Looks like you're hitting a classic SSH timeout issue when trying to connect to your AWS Ubuntu instance—let's break down the most likely fixes step by step. First, let's recap your setup to make sure we're aligned:

• You're using these commands (formatted for clarity):

  chmod 600 Hiko_key.pem
  ssh -v -i Hiko_key.pem ubuntu@13.54.24.220
  

• The error you're seeing:

  connect to host 13.54.24.220 port 22: Operation timed out

• Your debug output cuts off at the "Connecting to 13.54.24.220 [13.54.24.220] port 22" line, which means your local machine can't even establish a basic TCP connection to the instance's port 22.

Here are the key checks to run, ordered from most common to less likely issues:

• Verify your instance's Security Group inbound rules
  This is the #1 cause of SSH timeouts on AWS. Head to the EC2 Console, locate your instance, and click its associated Security Group. Go to the "Inbound rules" tab and confirm there's a rule allowing SSH (TCP port 22) from your current public IP. You can grab your IP quickly with curl ifconfig.me in a terminal. For testing, you can temporarily set the source to 0.0.0.0/0 (allow all IPs) but remember to revert this afterward—it’s a major security risk to leave it open.

• Check the Subnet's Network ACLs
  Network ACLs act as a subnet-level firewall, and misconfigurations here can block SSH traffic. Navigate to the VPC Console, find the subnet your instance lives in, and review its Network ACL. Ensure:

  • Inbound rules allow TCP port 22 from your IP (or 0.0.0.0/0 for testing)
  • Outbound rules allow all TCP traffic (or at least ephemeral ports 1024-65535, which SSH uses for return traffic)
    Default ACLs allow all inbound/outbound, so if you haven’t modified this, it’s probably not the issue—but it’s worth ruling out.

• Confirm the instance's public IP is correct
  If you didn’t assign an Elastic IP to your instance, its public IP might change when you stop/start it. Double-check the "Public IPv4 address" in your instance’s details page in the EC2 Console to make sure it matches 13.54.24.220. If it’s different, update your SSH command with the new IP.

• Test from a different network
  Sometimes local networks (like work or home routers) block outgoing port 22. Try connecting using a mobile hotspot or a different network. If it works there, the problem lies with your local network’s firewall or router settings.

• Check instance health and status
  Make sure your instance is in the running state, and that both "System status checks" and "Instance status checks" pass in the EC2 Console. If either check fails, your instance might have boot issues or hardware problems. You can try restarting the instance, or pull the system log via "Actions" > "Monitor and troubleshoot" > "Get system log" to see if the SSH daemon failed to start.

• Verify SSH daemon is running (if possible)
  If you have AWS Systems Manager (SSM) enabled on the instance, use Session Manager to connect directly without SSH. Once connected, check if the SSH daemon is active with sudo systemctl status sshd. If it’s stopped, start it with sudo systemctl start sshd and enable it on boot with sudo systemctl enable sshd.

Start with the first two steps—Security Groups and Network ACLs—since those are the most frequent culprits for timeouts. Let me know if any of these resolve your issue!

内容的提问来源于stack exchange，提问作者Ryan Achten