Network slows down to a halt eventually when connecting through router with cable modem

How do you resolve the problem eac time?  Restarting the PC? Restarting the router?

Are there other devices on the internal LAN, besides the router and the PC?

Is the slowdown aparanet on accessing the internet?  Accessing local network resources?

Have you tried upgrading the router's firmware?

I've seen situatons where a bug in the firmware caused the router to start dropping packets after it had been up for a while.  The bug was fixed in a later firmware release.

- I resolve it by renewing DHCP lease on router, sometimes shutting it and cable modem down, and renewing DHCP lease on computer.
- Local network resources remain okay
- Tried upgrading firmware, as well as two other routers - same problem

Huh.  No clue, actually.  If you've swapped it out for other routers, I assume of a different brand, and seen the same problem, then it sounds like a cable modem issue, but I really couldn't say.

Did you try a different type of router?

I would guess one of the two problems:

A: There is a compatability problem between the router you are using and the cable modem, I have seen this type of problem with NIC cards and cable modems. Use a different NIC and the problem is solved. In your scenerio, try a linksys or some other brand or router.

B: You have bad cable modem. Talk with your ISP, they are usually willing to swap out cable modems to try to solve the problem.

Do you have any hubs or switches in the mix??

Mike

 

Hey leekleiner,

1) Make sure the cables you use when you are connected to the Router are good.  Did you make them yourself?  Swap it out anyway.
2) Look for a "keep alive feature" inside the router (if they are giving you a dynamic IP)
3) Don't stack anything on top of the router.  If it heats up it will act funny.
4) Lower your MTU's to 1492 inside the router (default is 1500)
5) Try a different brand router just to test (not Netgear).

Make sure your system is not infected with Welchia worm? MSBlaster? the thousands of packets these worms send out will certainly cause your systems to crawl..

Have you tried adjusting the settings for lease term on the router?  

Are you doing file sharing?  Sometimes the lag a router adds will cause packet loss if there is too much "upstream" traffic.  That results in the acknowledgements not being replied to fast enough, which subsequently causes retransmit requests and packet loss, that can have a snowball effect.  Limit your outbound bandwidth if you are running stuff like Kazaa or WinMX, that should help.

BTW, I'm running on a Netgear RP614v2 now, switched to it from an SMC Barricade, and have had much fewer instances where I had to reset the router than with the SMC.

Thanks for the suggestions. I meant to say that I tried 3 DIFFERENT routers (Netgear, Linksys, D-Link) and same problem occurred. As far as my NIC card goes, since my computer works perfectly when connected directly to the computer, shouldn't that mean it's okay?
I will double check the virus/worm issue though, and swap the cables, move the router (it is in the furnace room, but it doesn't get that hot in there).

Given that o direct connect to the modem, there is no problem, that tends to eliminate anything on your PC that might be causing the problem.  Viruses, bad NICs, etc., would all show the same problem with the router, or directly with the cable modem.  That's why I huh'ed.

qwaletee -

If problem exists with different brands and models of routers, then it can't be a problem with the router - it would have to be with the cable modem or the PC.

If it works fine with a direct connection to the cable modem, then it has to be a problem with a router - any router.

That's where the upstream/downstream bandwidth and traffic loads come into play, because no matter how fast they claim to be, a router always adds a lag.  That added lag on top of overcrowding your upstream bandwidth can cause packet loss due to excessive retransmit requests.

No I mean don't stack the modem on top of the router it needs to vent (but it is pretty funny that it's actuall in a furnace room :-)
Also, if it's a "Speedstream 6360" get a new model!  I had the same issue utill I swapped out the modem - the replacement was a Speedstream 5100 and it works fine now.

Thanks for the suggestion, I tried ethereal and found that a large number of ICMP packets are coming from my PC. I haven't figured out what process is spawning them yet, but it seems interesting.
The IP that something is pinging gets incremented by one each time, for example:

192.171.182.124
192.171.182.125
192.171.182.126

etc...

Any idea what could be doing this?

I did a Norton Antivirus and did have the Welchia, but now that it's gone, I'm still getting these pings.

I'm also getting outgoing TCP packets which I would like to know their origin, but it's 99.7% (ICMP) to 0.3 (TCP).

Go to www.symantec.com like lr said but also do an online virus scan =-)

D

Welchia spreads to all unpatched win2K and winXP machines.  Make sure you update your systems asap.

If you follow lrmoore's links you will see that just running an antivirus scan won't remove either.  You have to use the removal tool or remove it manually.

Right and you also need to go to:
windowsupdate.microsoft.com on all machines and do the security patches to avoid spread / reinfection on the machines.  But a removal and scan will insure that the virus is not in other files.

D