Defense and Network Security

Est. read time: 1 minute | Last updated: December 17, 2024 by John Gentile

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Contents

• Network Protections
  • SSH
    • SSH Tunneling
• References

Network Protections

SSH

• Use Key-based auth for SSH to aid in passwordless SSH login/commands- usually as simple as $ ssh-copy-id <user>@<hostname/IP>.
  • How to Configure SSH Key-based authentication on a Linux Server
• How to Protect SSH with fail2ban on Ubuntu 22.04
  • Configure Fail2Ban for permanent and persistent bans

SSH Tunneling

SSH Tunneling can be used to forward certain ports or services over a secure SSH connection. It’s also useful if a local system wants to expose non-SSH services but only has an SSH port open externally through a router. For example, to tunnel Remote Desktop (RDP) to a remote server <remote>:

$ ssh -L 8888:localhost:3389 <username>@<remote>

You can then connect to the RDP session with localhost:8888.

Also you can forward multiple ports in one connection, for example:

$ ssh -L 8888:localhost:8888 -L 8889:localhost:8889 <username>@<remote>

References

• Computer Systems Security- MIT OCW
• Paged Out! Magazine

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