Articles tagged with ssh

  1. OpenSSH: Using a Bastion Host

    Posted on in System Administration

    Quick and dirty OpenSSH configlet here. If you have a set of hosts or devices that require you to first jump through a bastion host, the following will allow you to run a single ssh command:

    Host *
        ProxyCommand ssh -A <bastion_host> nc %h %p
    

    Change the Host * line to best …

  2. Removing a Single Line from known_hosts With sed

    Posted on in System Administration

    Ever so often, something changes on the network, and you find that your .ssh/known_hosts file has gotten out of date. Usually this happens after an upgrade or device change. You'll get the rather ominous warning that REMOTE HOST IDENTIFICATION HAS CHANGED!

    If you are confident that someone isn't doing …

  3. Rate-limiting SSH connections with iptables

    Posted on in System Administration

    If you have SSH open toward the Internet, you are surely aware of the number of brute force password attempts your server sees everyday. Although a good password policy may make these attempts nothing more than an annoyance, each connection to your SSH daemon takes up valuable server resources. I …

  4. Leopard SSH Slow to Connect

    Posted on in System Administration

    Orange Tunnel Thanks to a hard drive failure, I recently installed a fresh copy of Mac OS X 10.5 (Leopard) on my MacBook. I do a lot of work on remote systems and SSH is my bread and butter. Whenever I tried to SSH into other Macs on my local network …

  5. SSH Password Guessing Attacks

    Posted on in System Administration

    telescope

    I manage servers and network devices that, for a variety of reasons, allow users to connect via SSH from anywhere in the world. Although the traffic generated by these connections is encrypted, leaving this open to the world does present a bit of a security risk. Would-be crackers use compromised …

  6. You Too Can SSH Without A Password

    Posted on in Software

    I wrote recently about using Subversion over SSH. A minor annoyance with that setup is the need to enter your system password at least once, and sometimes multiple times depending on the action you are taking. There are also times when a remote system needs to access another system via …

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