Ask Leo!: Networking en-us 2008 Leo A. Notenboom and Puget Sound Software, LLC Sat, 24 Jan 2009 09:58:15 -08:00 Sat, 24 Jan 2009 09:58:15 -08:00 720 http://ask-leo.com/images/altile144.jpg Ask Leo! http://ask-leo.com 140 140 Tech Questions? Get Answers! Ask Leo! Can a MAC address be traced? http://ask-leo.com/can_a_mac_address_be_traced.html I know that all computers have a unique MAC address. But how traceable are they? If my laptop gets stolen, and I know my MAC address, can I get back to it if the person stole it gets connected to internet, even after formatting the machine and thinking that it's safe to connect? Seems like this could stop laptop burglaries if that MAC address thing is traceable.

]]> You're correct ... it could put a big dent in laptop burglaries if MAC addresses were traceable. Or it would at least increase the odds of stolen equipment being recovered.

But they're not. At least, not in any way that could help.

Let's look at why.

]]> leo@pugetsoundsoftware (Leo A. Notenboom) Sat, 24 Jan 2009 09:58:15 -08:00 Technology What's the difference between a Mac Address and an IP Address? http://ask-leo.com/whats_the_difference_between_a_mac_address_and_an_ip_address.html What is the difference between a Mac Address and an IP Address? Are both traceable back to your computer? And can you hide them? If by hiding them is your computer safer from hackers. Also, are the free versions as good as the ones you buy?

]]> Well, the last one is easy to answer: there's no concept of free versus paid IP or MAC addresses. As you'll see in a moment, IP addresses are assigned as part of connecting to a network, and MAC addresses are assigned at the time hardware is manufactured.

Even hiding a MAC or IP address is a concept that doesn't quite apply, but we'll get in to that too.

And whether MAC or IP addresses are hidden or not, if you connect to a network these are not the kind of things you should be spending your time worrying about to stay safe from hackers.

]]> leo@pugetsoundsoftware (Leo A. Notenboom) Thu, 24 Jul 2008 11:48:51 -08:00 Technology What is bandwidth? http://ask-leo.com/what_is_bandwidth.html Can you explain bandwidth to me in layman's terms? I have looked it up on the internet, but I get the standard mathematical explanation. My brain doesn't really work mathematically so I need something a little more tangible, or some examples of what is FAST and what is SLOW. For example, according to bandwidth.com, my download speed is 17237 kbps and my upload speed is 1615 kbps. I understand that means 17.237 mbps and 1.615 mbps respectively. But what does that mean? Is that fast? Slow? What do I compare it to?

]]> That's fast. Compared to me, anyway, that's fast. Given your ISP (from your email address) and the speeds you're seeing I'd guess you probably have cable internet.

I'm going to bring out the oldest metaphor I have to try and put a handle on how fast is fast. No math, but first just a teeny, tiny bit of computerese.

That part's inevitable.

]]> leo@pugetsoundsoftware (Leo A. Notenboom) Mon, 09 Jun 2008 14:08:32 -08:00 Technology How can I tell what program is making or accepting TCP/IP connections on my machine? http://ask-leo.com/how_can_i_tell_what_program_is_making_or_accepting_tcpip_connections_on_my_machine.html Another application is listening on my e-mail port 110 and it is restricting my ipo high speed. How can i find the other application?

]]> I'm not exactly sure what you might mean by "restricting my ipo high speed", but it's very easy to see what TCP/IP ports are in use on your computer. There's a command line utility to tell you exactly that, but there's an easier to use, and free, tool we can download as well.

]]> leo@pugetsoundsoftware (Leo A. Notenboom) Mon, 26 Feb 2007 20:25:50 -08:00 Technology Why do I get "There is another user logged onto your computer" when I shut down? http://ask-leo.com/why_do_i_get_there_is_another_user_logged_onto_your_computer_when_i_shut_down.html I turned on my computer and came back after 30 minutes or so to let Norton do its scans and so forth. When I tried to start working my computer was nearly frozen, so I tried to shut it down. I got a message that said "There is another user logged onto your computer if you terminate now they may lose there work" - so I quickly powered off but What's going on? this is a new problem and I have never accessed nor anyone else from elsewhere.

]]> Based on your description, I'd personally be concerned that your computer had been infected with some kind of malware allowing remote control.

But before we jump to such an extreme conclusion, let's take a look at just what that message means, and what you might consider doing to determine exactly what's going on.

"There is another user logged onto your computer" can actually mean a couple of different things.

]]> leo@pugetsoundsoftware (Leo A. Notenboom) Tue, 26 Dec 2006 17:31:36 -08:00 Technology