Forums | MacLife

Dave the Embalmer · 2007-01-24 4:02 pm

I live in a house with several people, and we have a wireless router (a DLink Wireless Extreme G router to be precise) hooked up to a cable modem. This network is a mix of macs and PCs.

Here's the problem: Several times during the day, the router acts like it's restarting (everyone sees their wireless/ethernet disconnected), but it happens far to quickly. It's like a brief flash of outage. Secondly, the cable connection itself goes down periodically. The line is still fine, all the lights are a-go on the modem, but the connection is just screwed. The only way to fix it is to power-cycle both the modem and router.

Now, under normal circumstances, I would diagnose this as a router problem and just get a new router. However, I've gone through THREE routers, and even swapped in a new cable modem, and the above problems still persist.

Here's a little history: Originally, the connection was crap. Downloading things (when it worked) was speedy, 500KB/s, average cable speeds. Surfing the web was horrendous. It was like it was having issues resolving DNSs and establishing a connection to a IP, but once it did, it was solid. Our connection was like this for a long time, but the one thing that helped is everyone limited their torrenting to 5KB/s up. That seemed to clear up the speed problem, but the network still remains rather shoddy and has the problems I mentioned in the first paragraph.

Any idea what could be going on, and how to fix it? I've talked to my ISP, and they have no idea. Every one around me has the same ISP, and they never have connection outages.

Dunkin' · 2007-01-25 8:30 am

Do you have the modem and router on an Uniterruptible Power Supply (UPS). Not just a surge supressor. But a battery backup power supply that conditions the AC power. Brief power fluctuations cause problems like you describe.

niclake13 · 2007-01-25 8:56 am

It could be that it's automatically renewing your lease on the IP... I'm not sure of the exact terms here, but the same sort of thing happened do me (Netgear WGR614), and I just had to turn off the auto-renewal of .... well, whatever it is. Can someone help? I'd actually like to know what it is that I'm talking about here.

-Nic

Dave the Embalmer · 2007-01-25 3:59 pm

That's a great suggestion. I don't have a UPS, but I can at least change what circuit it's on in the house. Although, I'm not sure if that explains the mysterious problems with torrenting. I'm thinking maybe it's something at the ISP level when it comes to that.

Thanks for your help, I'll give it a whirl and see what happens.

Dunkin' · 2007-01-26 8:23 am

niclake13 wrote:
It could be that it's automatically renewing your lease on the IP... I'm not sure of the exact terms here, but the same sort of thing happened do me (Netgear WGR614), and I just had to turn off the auto-renewal of .... well, whatever it is. Can someone help? I'd actually like to know what it is that I'm talking about here.

-Nic

DHCP lease can have a time limit. Set them to once a day (24 hours) to see if it helps.

brute44 · 2007-01-29 11:45 pm

Well it sounds to me like there could definitely be some power issues to describe the random rebooting of the modem and router.

To take DHCP out of the equation just have everyone statically set their ip instead of pulling leases potentially at the same time.

If you have that many people on the network doing heavy p2p, you could be causing the router to reboot due to the amount of Nat'ing going on. Residential routers aren't meant for heavy abuse, look for a firmware upgrade on that potential model. There could be a known issue with nat'ing or wan to lan throughput. The netgear 624's are a prime example.

Another thing to remember, cable is built for downloads not uploads. Its not a two way street. Often the upload speeds range from 128k to occaisonally 1mb depending on the cable provider, but they usually rank towards the initial figure. Also, cable is a part line infastructure. Everyone on you block shares the circuit, so if you live on a street with old people like me you can abuse it. big_smile

Sorry if I rambled, but working at an ISP gives me a lot of experience with these issues.

Last edited by brute44 (2007-01-29 11:46 pm)

Someone Else · 2007-02-04 1:01 am

I just posted this as I'm experiencing something similar with an Airport Extreme base station.

I'll try statically assigning IP's instead of the DCHP/NAT thing tomorrow I'm sort of fed up with it tonight.

ElectricSheep · 2007-02-04 1:24 am

brute44 wrote:
If you have that many people on the network doing heavy p2p, you could be causing the router to reboot due to the amount of Nat'ing going on. Residential routers aren't meant for heavy abuse, look for a firmware upgrade on that potential model. There could be a known issue with nat'ing or wan to lan throughput. The netgear 624's are a prime example.

Linux-based Linksys routers are particularly susceptible to crashing under heavy P2P loads. It turns out that as shipped, the Stateful Firewall was setup to track connections for five days. Lots of P2P traffic quickly filled up the dymanic ruleset, crashing the router. Upgrading to a 3rd party firmware like DD-WRT and then using telnet to change some configurations will fix this.

New models of Linksys routers are no longer based on Linux, and deploy VxWorks instead.

Forums | MacLife

#1 2007-01-24 4:02 pm

Networking Mystery

#2 2007-01-25 8:30 am

Re: Networking Mystery

#3 2007-01-25 8:56 am

Re: Networking Mystery

#4 2007-01-25 3:59 pm

Re: Networking Mystery

#5 2007-01-26 8:23 am

Re: Networking Mystery

niclake13 wrote:

#6 2007-01-29 11:45 pm

Re: Networking Mystery

#7 2007-02-04 1:01 am

Re: Networking Mystery

#8 2007-02-04 1:24 am

Re: Networking Mystery

brute44 wrote:

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