Monday, May 19, 2008

Al Gore must hate us.

Yesterday, I went to post some tips on how NOT to train for a race. These tips included dancing in high heels the night before a practice run, and fueling up with Munchkins (TM) the morning of a practice run (neither of which are normal activities of mine). I did manage to get through the extended distance (3.75 miles), but I didn't increase, or even meet, my furthest running distance - at least not my continuous running distance of 2.5 miles.

But all this is nothing when compared with our internet service going down!

Saturday night, our newly repatriated son had a group of friends over to play something or other on the computer. There were 4 guys, with 4 laptops, using up all our wireless bandwidth and rebooting the modem periodically. No problem (I was out dancing in high heel shoes so I hardly noticed the drop in service). I tell you this because I really suspected that this had something to do with the crash.

Come Sunday morning, our internet service no longer worked, giving us error messages like "IP address not working", "Unable to connect", etc. The thing is, we were able to connect - both our computers, with different operating systems, by the way, showed that our connections were very strong, but it seemed that the modem was unable to issue IP addresses to our computers. We contacted our ISP, Comcast, and they talked us through some stuff, but they couldn't understand it. They sent a technician over who told us that Comcast didn't lease enough IP addresses, or something like that, and that an update was done overnight on Saturday. There was nothing he could do, but that it might start again later. I thought the guy just wanted to go home - it was Sunday afternoon, but my son's internet connection, on our same wireless system, was working fine! AHA! What does this mean?

I called Comcast back to ask a few more questions about this IP address leasing problem, telling her that one system worked. She said that our modem may be broken and they scheduled coming by to replace it this afternoon. Since then, I've managed, or more likely, the Comcast service has managed to be able to issue IP addresses and now we're all able to get online.

It's frustrating, I tell you, to know so little about the technology that brings us so much. aargh.

Oh! I almost forgot: the worst part is that due to this interruption in service, we missed the first night of the OPAR seminar. In reading the requirements for the seminar, it seems that live participation requires an online connection, and frankly, all this frustration made us both incredibly tired by 9:30.


C. August said...

Comcast didn't lease enough IP addresses? I highly doubt that. Sounds like you got an uninformed answer from someone who just wanted to go home, as you suspected.

Most likely, you have one public IP issued by Comcast, and that is held by the "outside" of your wireless modem/router. All the computers within your little family network have "non-routable" IP addresses given out (leased) by the router itself. By non-routable, I mean that they don't work on the Interwebs. There are a few standard sets of non-routable IP address spaces, but the most common for home networks is the series. To the outside world, the traffic from your computers all takes on the public IP.

I could be wrong, but I doubt that each of your computers has a valid Internet-accessible IP address. You usually only get one of those with a home ISP account. All the computers on your home network go through that one pipe -- your modem -- and to the outside world they all have the same IP address. Your router does the job of brokering all the traffic and getting the packets to the correct computer.

Think of it this way. Your house has one physical address. Even when you all go out into the world, if someone asks any of you your address, you'd all answer "11 Strawberry Lane, Anytown, MA". But when you're all at home, talking to each other and walking around in the house, the physical address of your home doesn't govern your interactions. OK... this analogy is getting strained, but hopefully you get the picture.

Perhaps what happened was that you have a restriction on the number of local addresses that your router can give out, and when all the extra laptops were there it messed with the DHCP server on the router. Sorry... DHCP is the thing on your router that gives out the local "leased" IPs. But this doesn't sound right either, because there's no reason to restrict how many leased IPs there are on a local network.

So it sounds like the thing fixed itself. That's what happens with the DHCP leases. They have a shelf life, and probably after 24 hours or so, the IPs that were being held for your son's friends PCs expired and were released back into the pool of available IPs.

I'd guess that nothing was actually broken, but instead there's a funky or at least unneeded setting on your router that led to the problem, and that it won't happen again unless 4 gamers descend on your home network again.

LB said...

Thanks for the explanation. I am barely hanging on to understanding what you said, but it sounds good because it all but confirms my original convinction: if one comes home to a gathering of 20 year-old guys, there ought to be some noise beside the concurrent frantic tapping of computer keys. Geesh!