Traceroute is an indispensable and frequently used troubleshooting tool. It seems incredibly simple and straightforward, but there are some slightly more subtle details that many people are not aware of. This presentation from NANOG 45 is a great overview of traceroute in general as well as how the results can be misinterpreted.
There are times when it’s incredibly convenient to be able to stand up an FTP server without the need to actually install anything or reboot. I came across Xlight FTP for Windows and was pleasantly surprised to find that it didn’t require any installation and worked well with very little setup or configuration required. You basically double click the application and bind the FTP service to an IP address and TCP port and then you add a user account and assign directory permissions. Once done you click the “play” button and the server should start up.
Here’s a link to their page: http://www.xlightftpd.com/
They offer 32-bit and 64-bit versions as well as a “traditional” installer based version.
A brief history lesson:
Prior to the announcement from Cisco of “Universal Access Points” you had to select an access point based on which regulatory domain it would operate within. Regulatory domains are simply places in the world with certain laws and regulations pertaining to radio frequency devices (mobile phones, radios, access points, etc.). In the world of Cisco this meant that an access point for use in Germany would have a different part number than one used in the United States. This led to much frustration and confusion.
The good stuff:
Cisco has announced Universal AP’s which are a single part number per access point model (2700, 3700, etc.) rather than the myriad of part numbers aligned to each and every regulatory domain. The details on how this works can be found in the following blog post.
With the explosion of amateur electronics interest there is a renewed demand for basic electronics information. I’ve found the information available at All About Circuits to be well written, up to date, and easy to follow. In addition there are a number of courses available via edX offering beginner to intermediate level courses.
Need a simple, easy way to check if a piece of Cisco hardware is covered under warranty or SMARTnet? Look no further than this useful site: https://cway.cisco.com/sncheck
You will need to login using your Cisco.com (CCO) username and password, but then you can check on coverage for ANY serial number. If the serial number is covered under a contract associated with your CCO account then you will see additional details including coverage end date and coverage level.
TranslatorX is an indispensable tool for parsing Cisco Unified Communications Manager (CallManager) as well as Cisco CUBE logs and trace files. Check it out here: http://translatorx.cisco.com/
Twilio offers a wide range of services from API’s that integrate with your applications to SIP trunking services and phone numbers. I first discovered Twilio as I was looking for an easy to use API that offered two-way SMS/text messaging services. The fact that Twilio not only offers that services, but also can provide local phone numbers in a huge number of areas across the United States made their service all the more attractive.
I would highly recommend taking a look at Twilio should you need to integrated voice/SMS/VoIP services with your applications.
I recently discovered the excellent web based diagramming tool named Gliffy. You can think of it as a web based version of Microsoft Visio at a high level. In addition to network diagrams you can create flowcharts, org charts, sitemaps, user interface diagrams, etc. The import/export functionality works well and even supports importing Visio VDX files (not VSD though). Gliffy offers smooth integration with Google Drive.
A free account offers you the ability to test drive the capabilities of their platform with a few limitations including:
- Total diagrams are limited to 5
- Storage is limited to 2 MB
- Inability to create private diagrams (everything you create is viewable by anyone)
I encourage you to take their tool for a test drive at http://www.gliffy.com/
TACACS+ provides authentication, authorization, and accounting services for network devices. In simple terms this provides granular control over who has access (authentication), what that user is allowed to do (authorization) and keeps a log (accounting) of everything that user does.
Marc Huber has created and maintained a fantastic open source TACACS+ server for Linux available here: http://www.pro-bono-publico.de/projects/tac_plus.html
If you’re more inclined to the Windows world have a look here at a free TACACS+ server for Windows: http://www.tacacs.net
In this age of cell phones with caller ID (ANI) displays it’s easy to forget that there was a time when this feature didn’t exist.
If you’ve ever been in a situation where you need to learn what the caller ID is you can simply dial either of these numbers to have the caller ID read back.