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internet network goes out, but cable modem and router seem to be working

I am having trouble with my internet connection. I have a Motorola SB4200 and a Dlink DI524 wireless router. The cable modem shows connected and locked with activity lights and the router is blinking network activity as it should. But the internet connection is lost as much as once an hour, or sometimes less than one time a day with no pattern. Powering off the modem and router then restarting always solves the problem for a while. I noticed in my cable modem log file that I keep getting the following message "5-Warning D520.2 DHCP Attempt# 1 BkOff: 4s Tot DSC:1 OFF:1 REQ:1 ACK:1" I seem to get it when the internet is dropped. The modem has DHCP enabled with an IP range of 192.168.100.11-42 and the router also has DHCP enabled with a IP range of 192.168.0.100-199. The router shows the home network computers to have an IP address assigned by the router and not the cable modem. Do I need both the cable modem and router to have DHCP enabled. I could find no way to disable the DHCP on the cable modem. And, is the warning message in the Cable modem log indicating why I keep losing my internet? The wife is not happy about all the problems. So any help would be appreciated. This all seemed to happen when a thunderstorm caused my old linksys wireless router to have 3 of the switch ports fried and one of my computer's NIC card. I can communicate with the router and modem when the internet is working using IE. When it isn't working, I can get to the router's setup, but not the cable modem. I suspect the cable modem is tired and needs to be replaced. Let me know what you think. Attached is the cable modem log file.

Thanks Tom

Reply to
geoman39
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Your attached file won't appear for most people as this is not a binary group. Some folks won't even see your message minus the attachment. But it doesn't matter.

Your computers will get their IP addresses from the DHCP server in your router. Your router gets it's WAN IP address from the cable network. And your cablemodem also gets an IP address from the cable network for the cable network. (This is not the same IP address as the webserver in the cablemodem that you use to view it's status page.)

What seems to be happening is when you are power-cycling the cablemodem the modem is getting a short lease. A very short lease. And when it tries to renew the lease, it is unable to do so.

There are a couple of reasons I can think of why this would happen. One is that there is work going on in your area, and they want to make sure the modem checks for a new lease frequently. But then we have the question of why it can get one when you power-cycle it, but not in the normal course of renewal.

Another possibility is that the first lease you are getting when you power-cycle the modem is a temporary lease that allows brief connectivity for any modem put on the network. When that lease expires, a new lease needs to be issued by the regular DHCP server, which isn't issuing your modem a lease.

If there was a DHCP server problem, everyone in your region would be suffering the same fate. DHCP server failures can't go on for very long without causing major problems for the network, so we can probably rule out a server problem.

What that leaves, in no particular order, would be a problem with your account, a problem with your modem, or, if the problem isn't as consistent as it seems in your post, a line problem. Normally I'd say an account problem would be more likely, but since you mention a recent lightning strike, I'd move the modem to the top of the list of possible causes.

Reply to
Warren

When you got the new modem, did you notify the provider? Perhaps they did not provision the new modem properly, thus preventing it from renewing it's IP lease.

Jim

Reply to
Jim Banks

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