Thursday, March 25, 2010
The task can be daunting if you're not a network engineer, and I suspect many of you are not. But I just went through a "teachable moment" at one of my clients, and that, as well as Suzanne's excellent recent post about bandwidth, compells me to describe what happened and what it could mean for you.
The users at the site complained about slow Workflows responsiveness between 2 and 4 in the afternoon. Workflows was the only thing they complained about. I have some software tools to look at the circuit from the library to the Internet and that always looked good. It was always well below what the circuit could carry. The router at the edge of the state firewall was always very responsive (I've seen problems there in the past), so I did what I almost always do when I first look at a problem. I assume it's someone else's fault.
They continued to complain. It would sometimes be so bad their Workflows application would close. This makes it hard to run a library. So, the next time I was there, I downloaded and ran a free program called Ping Plotter (www.pingplotter.com/freeware.html). It is basically an enhanced traceroute program. If you don't know what traceroute is, you should probably give this post to your tech. I point it to any place out on the Internet and see how responsive the path is. When troubleshooting Workflows, I always point to 188.8.131.52 because that is the last router I can see before the route goes inside the state firewall.
Within seconds after starting this tool I could see there was a problem, a big problem. Most of the packets our library was sending to the Internet were not being responded to. We were seeing frequently more than 70 % packet loss. It was amazing that any of our applications were working at all. The curious part though was that we were seeing packet loss at all hops, not just one bad spot having trouble. Sticking with my previous assumption, that its someone else's fault, I called Qwest. The Qwest guy was fantastic, but basically he proved to me that it wasn't his fault. And furthermore, he also proved that the problem was inside the building. Uh-oh, it looks like my fault.
This site has a CentreCOM 24-port switch they got from one of the early Gates hardware distributions in Montana. I think this came with the 2002 distribution. When I finally replaced it with a different switch the problem was gone. The switch had just gotten to the point where it could not reliably move packets through itself and it looked like the problem was a bad Internet connection. Or actually, it looked like a bad Internet connection, until I used the right tool to look at the problem.
So one moral of the story is try using ping plotter. Its free. Its easy to install. It might point you in the right direction if you are having a "slowness" problem, chronic or otherwise. It does require a little understanding to be able to use it.
Another is to be suspicious of these switches. Maybe this one had just been mistreated at some point, but maybe they are getting old as a group.
Another, possibly, is to not assume initially that it's someone else's fault. Naa... I think I'll continue to do that.
Friday, March 12, 2010
The answer is, you run a speed test. There are several out there. But I'd like to call your attention to this one because it's being conducted by the FCC. The data may go into the National Broadband plan.
You do need to have Java running on the computer you're testing.
If you want to share your results and see what other libraries are getting, you can enter comments to the post.
Montana is running its own speed test for broadband mapping. You probably want to participate in this one as well.
I've been asked by several people whether or not they should be concerned if they get different results from different tests. I don't think you should be concerned. Your speed can be greatly influenced by what tasks are being done by others on your network at the time the test is taken. As an example, I ran a speed test while I was downloading 2 200 MB podcasts. I got 3.44 Mbps. I ran the test again right after the podcasts had downloaded and got 5.1 Mbps. Audio or video downloads, streaming video, online games can all greatly affect your speed.
Sunday, March 7, 2010
I have had a couple incidents recently that highlight the usefulness of a tool I have been using of late and I thought I would pass on the name. The tool is called “Web of Trust”. You can download and install it from www.mywot.com. It is a tool you would use on your own PC, either at home or work. I don’t think it’s worth the effort to put it on a public surfing PC.
It's an add-on for your browser and you can install it on IE, Firefox, or Chrome. If you run all three browsers, you will have to do an install for each one. Then, of course, you have your staff PC, your staff notebook, your home PC, your spouses’ PC, and so it goes. There could be a lot of installing.
The idea with the Web of Trust is that you and I and the other users of the web have opinions about the reliability of various sites. Sites are rated based on these opinions and your browser will show you the results of these combined opinions with a red, yellow, or green circle on a site.
For example, I did a Google search for free music. A portion of the results are posted below.There are two red circles, and two green circles. I wouldn't go to the sites indicated by the red circles but I would go to the sites indicated by the green circles. If there were any yellow circles, I may have a look at them, but I would be pretty wary.
There is more to the Web of Trust than just colored circles. It can pop up warnings for risky sites, and you can get more information on a given site by clicking on the circle associated with that site. It is a useful tool that can help you stay away from risky sites. This would not be useful on Public PC though because patrons on our PCs don't care whether a site is risky or not.
Let me give you a couple examples how this was useful for the two incidents I mentioned earlier.
One of the staff here received the email shown below. Now there are a lot of reasons why this would look suspicious at first glance, and so she got suspicious and asked me about it. Well the “click here” phrase is a link. You know that you can put your cursor over a link in your email program and it will show you the link before you click on it. When you’re doing this make sure you DO NOT CLICK on the link. So this link had a URL, the domain of which I Googled. The hits that came back had a lot of red circles, just confirming her suspicions.
From: Smith, John [mailto:firstname.lastname@example.org]
Sent: Thursday, March 04, 2010 9:13 AM
Subject: Your E-mailbox Has Exceeded Its storage Limit.
Your mailbox has exceeded the storage limit which is 20GB as set by your
administrator, you are currently running on 20.9GB, you may not be able to
send or receive new mail until you re-validate your mailbox.
To re-validate your mailbox please
Thank you for your cooperation.
Webmail Help Desk.
Another user here had discovered a database on the web look at every driver’s license in the US. She was appalled by this and sent an incredulous email with the URL to me and some others. Well, I’m sad to say, I bit. But as soon as the site came up in my browser, along with the red circle, I knew it was bad and just closed out the browser. Then I Googled again and found a comment about the bad site at Snopes. The bad site is probably nothing more than a prank site, but we really don’t know.
Snopes keeps track of urban legends and rumors. Find out about the drivers license site by going to snopes and use their search tool for “driver’s license look-up”. I am not going to give you the link to the driver’s license site itself.
You should have a look at snopes if you haven’t yet. It’s at www.snopes.com and it gets a green circle. Also try out WOT. Be careful out there, and may all your hits be green.