What's NSM you say?  We'll go with Network and System Management, but you could throw Security in there as well.  We'll work our way through the alphabet over the next several weeks looking at tools and concepts along the way for all the administrators out there.  By the way, you can thank Joe for the format & Don for the title (I couldn't for the life of me come up with one.)

Today's letter A is for arpwatch, a utility that keeps track of mac/IP pairings.  This has obvious upside for making sure IP's aren't switching in non-DHCP environments, that mac addresses are not showing up unexpectedly, and for historical record keeping in dhcp environments for when you need to track down which mac owned a particular IP when combing proxy logs for potential security policy violations. 

Another possible use case is for server environments that use DHCP.  If you are delivering their applications on the BigIP, then managing the pool members with constantly changing IP's is an administrative headache.  Enter iControl.  With an iControl app tracking the arpwatch output, the pool members could be automatically updated to reflect the changing IP addresses, eliminating the need to manually track this process.  Cool, huh?  Just make sure you know which mac's belong to your servers, okay?  You wouldn't want an unauthorized clone of your servers accepting authentication requests...

Honorary Mention: AxCrypt

AxCrypt, from Axantum Software AB, integrates into the Windows Explorer, allowing you to encrypt/decrypt files from the right-click menus.  This can be done with passphrase, keyfile, or both. The application extensions are remembered, so double-clicking will launch the appropriate app, and the files will be re-encrypted automatically after modification.  Great utility for teams that work with sensitive files and need to pass them around, or for an individual who travels frequently and doesn't want to compromise any important data if the laptop is lost (keep the key on a thumb drive in your pocket).  You can integrate AxCrypt into your scripts, and you can also shred your documents upon deletion.