Router keeps dropping WAN connection

I have a small workgroup, with 6 PCs running Win XP Pro. One is used as a gateway and a file server, the rest connect to the internet via ICS (and it's rudimentary DHCP) and we use an 8port 10bastT switch. We have software firewall. There is also a Ricoh 2035s/p scan copier using a scanRouter software and a static IP. This setup seems to work fine, except for the fact that I want to get a faster throughput (than 10baseT) and I want to get a more powerful firewall.
On two occasions, I have installed an 8port router - one time an SMC and the other time a Linksys. Both times the same thing happened: The connection went smoothly for about 10 minutes. Workstations could see eachother's shared resources, print to the Ricoh, and get email and internet. Then out of nowhere, the external side loses connection. The router interface cannot renew an IP, and no one can get out to the internet. However the internal communications are still up and running. If I cycle the power on the cable modem, and let it go through it's startup and discovery process, it gets an IP on the internet side again, for a short time (anywhere from a few seconds to 30 minutes or so). Then it drops again.
My thought is to get a 10/100 switch rather than the router, and purchase a more powerful firewall software. Then let the XP Pro PC handle DHCP using ICS and stay with the setup I already have. However, this is my second choice, and I wonder if anyone has any idea what could cause this [roblem?

Thanks,
Johnny5

 

Sounds very much like imminent modem failure, since powering down repairs everything.

 

I am thinking in that direction, so I am having the leased modem replaced. However, it has me puzzled that the modem does not impact connection in that way when I use the gateway PC/ICS setup, only when I use a router. No loss of connection is percieved when I have it set up to have all the clients access the internet through that one gateway PC, and we can leave it on for weeks.

 

I would bet on a conflict between ICS and the Router.

ICS sould not be needed ( or even in the picture ) when using the Router.

BillyBob

 

With a router in the system, duplex settings are usually recommended to be set at 100Mbps/full. Not sure if that would affect connectivity at the modem level though. Would speed up networking. Have you tried resetting?

 

I have been turning ICS off when I hook up the router, so it shouldnt be in the picture. I have also turned off the XP firewall. I have not looked at each workstation duplex settings - I will have to check on that when I am in next. The router and modem have been reset many many times - this is an easily duplicatable problem, it just varies how long the connection lasts. I have observed no errors in Event Viewer that would suggest a service failing or a conflict in TCP/IP. There is a new modem in the picture now, I will try again later this week - any other suggestions for when I get started?
Thanks!

 

None here. I think the new modem and duplex settings with router will solve your problem. Fingers are crossed. Let us know...

 

Yes, a new modem seems to have done it!
Thanks to all who input.