HiddenOne

You just landed that new networking position after months of interviews and waiting! If you’re lucky, the hard part is over and you will slip into a position where the network paracticly manages itself. Meanwhile, back in the real work…

Network administrators are like software developers. That is documentation is usually an afterthought, and sometimes it is not a thought at all! We have all faced this problem. This is the situation that I walked into this past summer. The key here is not to look at the situation as a problem, but as a challenge.  Our largest building was our biggest challenge. The cabling was not done in a structured manner, and in some cases I was baffled how some of the “redundant links” did not cause network loops since STP was not activated.

The biggest challenge in this building was troubleshooting link problems between the switch closets. Dropping the link from one cabinet to another would cause half the building to go down in some cases. Without proper network documentation, we were left in the dark. With the way the cabling between the switches was laid out, it would be a copious amount of work document this by hand. Enter Solarwinds with their LANsurveyor product.

LANsurveyor can be used to create network maps with a minimal amount of information. In my case, I was able to create a network map for each of our seven buildings using nothing more then the IP address range for that building and our SNMP community strings. Even if your community strings are not standardized, changing them on your devices would be considerably less work than creating a manual network map.

This convenience does come at a price. The version I use sells for about $2000 and is a standalone piece of software. There is a $500 version that integrates with Visio, but I have not used that so I cannot comment. You do have the option of downloading a trial before you purchase the software. If $2000 is not in your personal budget, you may be able to sell the software to your boss if you calculate all of the man hours it would take to map your network by hand!

Below are some screen shots of LANsurveyor, one of which shows the chaotic network map for the building I mentioned above.

LANsurveyor network discovery settings:

Sample Network Map (I zoomed out so you can see how difficult this would have been to document by other means):

Note: This is not an advertisement for Solarwinds, and thus I am not profiting from this post! If you have used other software to solve a similar problem, please share your experiences in the comments section.

General

The past five months have been crazy! I landed my first network related job, as a network administrator. As soon as I started there was a major project to put a new network in the one building over the summer (cabling and all). That was followed by some slightly smaller projects, such as an upgrade to our main router. On top of that I have been busy with personal projects, including working on my car.

Unfortunately all of this caused many things to fall by the wayside. This site and my CCNA study where two major things that I fell behind with. The past few weeks I have really stepped up my CCNA study. The down side of that is that I have had to review many old topics and my books are now a version behind the current CCNA tests.

I am going to try to update this site more often. One change I am going to make is the renaming of the “VMware Whitebox” section. I have not given up on that, but I have decided to play with some ofther virtualization options. That means I will be setting up and playing with Windows Sever 2008 with Hyper-V! I am hoping to get this setup soon and share my setup here.

General

Recently I came across a situation where I wanted to delete selected files from the Flash memory on my router. In order to delete the files, I issued the following command:

delete flash:/file.bin

After doing that I was surprised to see that the files were only marked for deletion in flash, which meant they were also still occupying the storage space I needed for other files. In order to permanently delete the files, the following command needs to be issued:

squeeze flash:

After trying to run the squeeze command, I received an error saying no squeeze logs could be found and the operation failed. After some research I discovered that you need to run squeeze on the flash memory while it is empty (I later found you can do this with just the IOS image in flash). Here is the process I followed.

1. Make sure you have a backup copy of the IOS image you want on the router.
2. Format flash (Do not reboot the router after this)

   erase flash

3. Reload the IOS image into flash.

   copy tftp://xxx.xxx.xxx.xxx/ios_image.bin flash:/

4. Run squeeze on flash

   squeeze flash:

After all of this is completed, you will be able to mark files for deletion using the delete command and then permanently delete them with the squeeze command.

General

Here is a song from someone at RIPE 55. I thought it was a great piece!

The Day the Routers Died

General

With the arrival of the 3524 switch, I ran into the first situation where I had to reset the password on a switch. I have performed this process in the past on routers, but even the CCNA book I have did not cover the process on switches. The process is quite different when compared to the password recovery procedure on a router.

Cisco calls this process password recovery, as opposed to a password reset. The goal is to maintain the current configuration on the device, in this case a switch, while allowing you to reset the PrivilegeEXEC and Telnet passwords to something you can remember. In my case, I skipped the last few steps in the Cisco process since I was not concerned with saving the configuration on the switch.

This is a good page to bookmark, since you will likely encounter a situation where you purchase a used switch that will have a password set by someone else.

Cisco Switch Password Recovery

General

After much thought, I decided to create this web site. My main motivation was to share some of the things I have been working on for the last couple of years, mostly related to networking.

Pursuing my CCNA certification, has been a goal of mine for over a year now. Only recently have I started to regularly train and study for the exam. I have had a small lab for about a year now, and it is just now seeing some proper use.

Eventually I hope this site turns into an open forum where people can share their thoughts, experiences, and opinions.

General