I run a variety of programs including anti-spyware, anti-trojan, anti-virus and anti-malware. I don't run them all at the same time. All updated with the latest definitions, all five report a clean machine.
I use a large hosts file which can cause a slowdown with XP so I disabled the DNS Client Service. No change.
I changed the DNS Server Address to manual. No change.
What is changing in relation to my cable modem when I reboot? Something in XP gets crapped up but it clears upon a reboot.
For the sake of argument, let's say your unspecified anti-* programs are doing their job. That's a big assumption, so don't hesitate to come back to it later, if other things don't pan out.
You seem to be focused on DNS here, so the obvious question is, in what way do you think your "cable modem" is slowing down? My first assumption was a slowdown in throughput, but you apparently mean something else. Can you describe what you're seeing?
Do you have a wireless network that someone else has joined? Do you have a LAN with other active PC's? Do you run P2P software? Do you monitor your PC's network activity? Do you monitor your PC's CPU and RAM utilization? Do you have a router between your PC and the modem?
My ISP has their own online speed test. As I surf the web, I notice it's taking longer and longer to connect to web pages, etc.. I run my ISP's speed test. The results are slow: Download Speed: 69 kbps, Upload Speed:
17 kbps. Rebooting the modem didn't return the speed, but rebooting the modem and the computer did return the speed: Download Speed: 452 kbps, Upload Speed: 182 kbps.
I have since experimented and found I only need to reboot the computer.
I notice you didn't really address the above question.
No wireless network, no LAN with other active PC's, no P2P software and no router. When my cable modem connection slows down the rest of the computer runs at it's normal speed.
Sure it is. There's a lot of crap software out there being sold and marketed to do things that they don't do well, but let's move on. I can't force you to mention any names if you don't want to. :)
Are those speeds normal for your unspecified ISP? The download seems low by a factor of 10, (considering that this is a cable newsgroup), so is it possible that you mean kilobytes rather than kilobits? On the other hand, the upload speed only looks low by half. Confusing.
The questions immediately following were intended to try to help answer your question above.
No router, so your PC is directly connected to the cable modem? In that case, it seems likely that your PC is being compromised. You never mentioned whether you're watching your network activity and your CPU/RAM utilization, and I'll add a request to investigate the running processes (via TaskManager) to see if anything strange shows up. Of course, not everything shows up there, but it's a start. It would be very interesting to see if there's a lot of network activity when your PC is supposed to be idle.
Which web browser do you use? Do you have any browser toolbars or extensions installed? Some of them try to intelligently pre-fetch pages that they think you'll visit, so that can take up bandwidth that you wouldn't know about unless you checked your network activity.
Just trying to think out loud here, since it's been difficult to get meaningful details.
I suggest separating DNS issues from throughput issues as a means of troubleshooting further. DNS is typically used to convert (resolve) a domain name into an IP address, so that activity normally happens at the very beginning of a request. Do you see a too-long delay while your browser says it's trying to contact the site? On the other hand, if the name resolution isn't the problem and you're concerned about slow throughput, then forget DNS and look at what else is happening on your PC that's taking up CPU time or network bandwidth. An easy test is to temporarily swap in a different PC and see if it exhibits the same symptoms.
If nothing else, I strongly recommend adding a router between your PC and cable modem.
Good come back! McAfee and Norton you can pay for. I don't use those. Avast Anti-virus is free for home use and it works. a-squared is free and it works. You don't have to pay for something to be good and to do it's job.
Another good come back!If the computer is not compromised, then what is rebooting doing to bring my modem speed back?
No, something is slowing your network connection to the Internet. The cable modem is just one element in the chain, and is one of the least likely elements to be causing a slowdown. A cable modem is basically a bridge, so in the vast majority of cases, it either works or it doesn't.
Why not. Crackers are creating dns entries with a short life time to servers of their malware. Your system may be part of that network and it takes awhile for the bot master to get back to using your system.
Check for yourself
what if your AV misses 1% of 600,000
NOTE: Following urls pulled from stuff I read 2006/2007. No idea if they are still valid or not.
When was the last time you booted in the safe mode to do a Antivirus can of your system.
everyday and several times I see them talk about some new piece of malware and sometimes they say something like only 2 or 3, or 4 or 6 out of 32 AV vendor products were able to detect it as of this writing. :(
Some AV product is just another AV product repackaged under another name. All AV products have to catch a copy of the malware, figure out how to find it, test it, deploy to server and you get the download installed. Thats about an 18 hour turnaround to get you protected.
Saw an article where the malware was constantly being morphed to foil the scaners and infected websites had malware watching the ip connecting to it. If it was a known AV hunting site, regular content was served up. If ip was not in the database, it would try and push out malware. That means AV vendors have a harder time getting it for their product to detect it.
Saw an article where a couple was selling some malware for a year before the AV crowd received a copy to look at.
Some malware goes after the AV software on the system and makes it skip reporting it. Malware count crossed 600,000 quite awhile back. Some AV vendors are dropping signatures for old malware to keep performance up on their product. :(
You say you play safe hex on the internet and try to stay on safe sites. Here
click Last and work backwards to see the kinds of sites with known exploits.
Bank of India was cracked not long ago and was serving up malware. Pfizer had been cracked for 6 months.
for software with known exploits.
Some other links to give you a warm feeling about AV software.
?p=475 My solution, quit using Micro$not and run linux.
Do you have any idea who your ISP is? I don't think it's their problem, but I'm curious who it is because I've never heard of such low speeds being offered by a cable ISP.
Is it possible that they throttle you after a certain amount of activity?
Well, the indicators point to your PC. That's all any of us can go by.
Nothing personal, but we have no reason to trust that you perform safe hex. After all, you have a problem you're trying to fix, so apparently the condom broke, if you know what I mean.
Firewalls are notorious for bugging their owners to the point where the owner allows something that they shouldn't have allowed, or they allow something that later gets hijacked by malware. A router makes a better firewall than a firewall does.
You said the slowness takes awhile to show up, so be patient and keep monitoring.
It could, especially since your connection is throttled down so low to begin with. You're not that far above dial-up speed, so any extra network activity might be enough to be noticeable.
You keep saying you're losing your "modem speed". I know what you mean, but it sounds funny because the problem likely has nothing to do with your modem.
Your firewall is on the same PC you're trying to protect. There isn't a whole lot of protection there.
It has not been proven that your computer has not been compromised, or infected by a virus or a trojan. As you have stated, rebooting the computer cures the slowdown for a period of time. That proves it is not your modem. It could be an application on your computer has a memory leak. Or maybe as another person noted, you may be getting throttled by your ISP.