this is a pretty lengthy post and it might belong in the connectivity forum, but i wanted to give all the details and since it involves a wireless router, i decided to put it here.
i have two computers (both running windows xp sp2), a cable modem (motorola sb5101), and a 4-port wireless router (netgear mr814v2). i connect the main computer to port number one on the router via an ethernet cable. i connect the second computer to the router wirelessly. yesterday morning i switched cable companies and we are now with comcast. i had absolutely zero problems with this setup with our old cable company. everything worked fine until we made the switch to comcast this morning. nothing has changed except the cable modem and the fact that we are now getting service from comcast instead of from our old provider. the old cable modem is a motorola sb4100.
i set up my cable modem / wireless connection yesterday morning when the tech left (self-install, of course) and everything was working fine. but then i started to notice that the internet goes out on both computers about every 45 to 60 minutes and it'll stay out unless for about five minutes after which time it'll come back on by itself. if i happen to be using the computer when this happens, i can fix the problem immediately as follows:
1. undo the ethernet cable from port 1 on the wireless router and plug it into the cable modem directly (removing the exisiting ethernet cable from the back of the cable modem -- the one that leads to the input on the router). then release and renew the ip address to get the internet working on the main computer (but not the other computer since the router is now out of the loop).
2. plug the the router back into the cable modem and hook up the main computer to port 1 on the router. release and renew ip to get everything working on both computers.
this procedure will give me solid internet for 45-60 minutes and then i have to do it again. it doesn't seem to matter whether I am using the computer for that 45 minutes or not -- it happens either way. needless to say, this is very annoying -- i like to be continually signed on to the AOL Instant Messenger because i give technical support to some customers this way. even if i'm not there i generally leave an "away message" and folks leave me messages to answer when i come back. but of course they can't message me if i'm signed off (which is what happens when the internet goes down). of course, i can set it up to save my password and automatically sign back in when the internet comes up but then my away message will be gone and folks will think i'm ignoring them when in fact i'm not around.
i thought this issue was somehow a problem with my router so i decided to just take it out of the loop for an extended period of time. lo and behold that when i connected the cable modem directly to my main computer via an ethernet cable, the same problem happens -- internet is solid for about 45-60 minutes and then goes down. if i release and renew the ip address, it immediately comes back up. one thing i notice is that right after renewing the ip address, my dhcp lease is only one hour. and then after about ten minutes it'll change to 3 or 4 days from now.
of course a simple release/renew doesn't do any good when i've got my router in the loop because release/renew talks to the dhcp server in my router and not comcast's dhcp server. so i have to unhook the router and then release/renew and then rehookup the router as described above.
it seems like the one hour dhcp lease might be the source of my troubles (ie, it goes dead when it tries to renew the lease), but like i said in the previous paragraph -- the one hour lease generally only lasts a couple of minutes and then it gets updated to several days.
any ideas what's going on? and what's up with these one hour dhcp leases? surely comcast doesn't do this on a regular basis do they? i've had a cable modem for since 2001 and have never noticed such foolery.
let me close by saying that i have not yet called comcast about this because i'm guessing they'll tell me they don't support customers who have wireless/networking issues (although since the issue happens even when my wireless router is out of the loop i may call them the next time the internet goes down).
My wireless connection also goes out every 5-10 minutes or so. Comcast claims that it is not their system. Everything had been working fine for about nine months, then in the last six weeks it has been cutting out every day, all day.
Comcast recently "upgraded" the speed of their network. I suspect something is interacting either inside their network or with my configuration.
I am considering installing a new Motorola modem/wireless router combo and giving back my leased Comcast router.
I would like to hear if you get your problem resolved.
i went to netgear's website and started poking through the help / troubleshooting webpages. several of them noted that the majority of problems are solved by simply power cycling the router and the modem (in the order specified on the website). i had not powered off the router since in theory none of the settings had changed. i was still using the ISP's DHCP server to get an ip address, etc.
i didn't think doing this would solve any problems, but i did it anyway. i left both the cable modem and the router powered off for about 20 minutes and have had zero problems since powering them back on.
i've been siged onto AIM for the last 24 hours with no disconnects and am happy that such an easy fix solved my problem. if i had thought that this would be the fix, i would have done it first. i don't understand why this works snce none of the settings changed, but i'm willing to accept this as a solution to my problem.
of course, none of this explains why i had problems when my router was out of the loop, but since i never take it out of the loop i'm okay with this solution.