Speed Up Cross‑Data‑Center Access with SSH Tunnels and Port Forwarding

Reference: http://blog.creke.net/722.html

Background: Several data centers have varying network speeds, so the fastest center is usually chosen as the VPN entry point. Direct VPN access to other centers can be slow, prompting the use of an SSH tunnel as a temporary solution.

Use case: Accessing idc1-server1 is fast, while accessing idc2-server2 directly is slow, yet the connection from idc1-server1 to idc2-server2 is quick. Therefore, idc1-server1 is used as a jump host.

ssh -i /path/to/sshkey -l username -f -N -T -L 8088:idc2-server2:80 idc1-server1

After running this command, opening http://localhost:8088 in a browser forwards the request to http://idc2-server2 through the secure tunnel.

Key parameter: -L 8088:idc2-server2:80 forwards a local port (8088) to port 80 on the remote host idc2-server2. The local machine listens on the specified socket; any connection is encrypted and sent via the tunnel (through idc1-server1) to the target.

ssh -i /path/to/sshkey -l username -f -N -T -L 2022:idc2-server2:22 idc1-server1

With this tunnel, files can be transferred using SCP through the jump host:

scp -i /path/to/sshkey -P 2022 upload_file_name.tgz dong@localhost:/path/to/upload/