Flakey Network

[JohnBullard]

The past couple of days my network has been acting weird.

First I lost wireless on two of my computers, and finally was able to get another one to connect. My wired computers were fine.

On the two desktops that lost connectivity, they couldn't even see a signal, even though putting my notebook next to them, I could, although signal was weak.
Using channel 6 all in G mode.

Thinking my old microsoft router was flakey, I bought a Linksys WRK-54G.

After setting it up, all three wired desktops and the network printer worked fine. One of my wireless desktops, notebook and PPC would connect. The original 2 wireless desktops would not.

Put a new PCI G card in one desktop, no signal. Changed the router from channel 6 to channel 1 Bingo, both wireless desktops connected.

This afternoon, lost internet access on ALL computers, wired and wirless.

The cable modem showed good. All lights on the Linksys router were on (except DMZ).

Could not even ping from one wired desktop to another wired desktop. I would have thought this LAN should work even without outside internet access.

Finally I recycled the cable modem, no change. Power cycled the new Linksys router and now all is fine.

What in the world happened? Every item, all computers, cable modem, router, and switches are connected to UPS's, so I don't think power surge would be a problem.

Any ideas?

 

[electron]

Is there any chance that for some reason the Windows XP firewall turned back on, on some of the machines? That's the first thing I would check. I would also try pinging the computer's own IP address (i.e. if your IP is 192.168.0.101, ping 192.168.0.101 from that same machine) to make sure the IP stack wasn't corrupted by something. I would focus on the computers with a wired connection for now, just to eliminate any potential wireless problems.

Also, verify with the 'ipconfig /all' command that everything is still ok. If you can't figure this out, create an account with logmein.com if you don't have one already, and invite me as a guest, I would love to figure this one out.

 

[JohnBullard]

E,

Thanks for your thoughts.

Once I power cycled the cabled modem, then the router, all is working well again.

What's confusing to me (and it doesn't take much) two different routers (the old microsoft and the new linksys) both exhibted similar behavior within two days.

I do have two switches in my wired network, a 4 port linksys print server, network to USB printer - don't use this function, and a new Netgear 5 port Gig switch. Can't imagine how either of them would effect wireless though.

I do have logmein on one of the wired machines, if this continues, I'll take you up on your offer.

Most frustrating part being the new linksys router handled things differently then the microsoft one. Example - my network printer used an address of 192.168.2.217 and my homeseer server was 192.168.2.187.

No matter what I did on my old network, these (and all other machines) always reconnected with the same address they had before.

Now with the linksys, every reboot assigns a different address.

Finally got a static IP address assigned to my network printer, but found that I'm having to delete the software and reinstall on each machine b/4 it will find the network printer. Only two more boxes to go on that.

I think its time to assign a static address to my HomeSeer box also, will try to figure that out this evening, never done that before either.

 

[JohnBullard]

Ah, HS2 box now has a static IP address. The last couple of days, running around and restetting all of the remote speaker clients and changing the port fordwarding on the router got old fast.

All seems well now.

 

[electron]

I am probably too late, but your Linksys router doesn't allow you to reserve the IP address? But I do agree that static is the way to go.

 

[JohnBullard]

e,
Possibly it does, would know if I had read the instructions

 

[elcano]

Once I got a problem when some WiFi Pocket PC devices could not get any signal even when very close to the access point. However a laptop would get the signal perfectly.

The problem was that there was another AP in the same channel withing range. The radio of the Pocket PC could not discriminate as well as the radio on the PC and the signal just got cancelled or suppressed. Once one of the AP got the channel changed the problem was solved. The situation is similar to what happened to you, with the exception that we dont know if you have another signal in Channel 6 causing interference.

 

[JohnBullard]

Thanks elcano,

Not sure about another wifi network near me, nothing else comes up when I search for networks on my notebook.

None of my neighbors are tech savy, all are either retired or elderly widows, etc.

Heck, my closet neighbor didn't even install garage door openers until last year, when it finally became too difficut for him or his wife to raise the doors.

My thought (since two different routers behaved the same) was possibly interference from a 2.4 gig wirless phone - someone's new Christmas present?

All of my wireless phones are 900 Mhz for that reason.

Everything seems stable now, we'll see if it lasts.

If not, I'll put out the SOS for electron to remote in and see what he can find.

 

[JohnBullard]

Update:

Kept losing my network (again) tonight, off 5 or 10 min, on 5 or 10 min.

I started remembering a post(s) from last April on broadbandreports.com regarding a problem with Comcast DNS servers.

They posted a whole list of DNS servers (many public) to change to.

I changed (specified) the new DNS servers to use in my router, and so far all is fine.

Didn't Skibum or was it smee have a similar problem a few weeks ago?

I'll leave these DNS servers in my router for a while and see if things are stable over the next few days.

e, couldn't stay connected long enough to send you an SOS, but I could ping my own machine, just nothing else on the LAN side. Shouldn't I still have LAN connectivity even if the internet connection is lost? Couldn't even connect to my router.

 

[Mike]

That's strange you needed to change the DNS addresses. By default, comcast should be supplying them to you when you get your IP via DHCP. This would not have worked if you had explicitly specified DNS addresses earlier, so the dynamic ones would not be used.

Had you specified DNS addresses explicitly previously? If not, it is possible that there is another issue at play here as well.

 

[electron]

Next time this outage happens, try pinging your router by IP address. If this is a DNS issue, then it's an easy fix.

 

[JohnBullard]

As soon as I made my last post, it went out again!!!

I did try pinging my router, 192.168.2.1 request timed out!!!
The only thing I can ping is the machine I'm on right then - pinging myself

I did power cycle the cable modem and the router to get connected again

Mike, Comcast uses only a few national DNS servers, other Comcast users had reported no connectity when Comcast had a DNS server go down, or was overloaded. Guess changing DNS servers didn't work for me!! Must be another issue that just started on Tuesday evening.

Now what can I try since I replaced the router yesterday. All wired and wireless connections drop out, although all of the cable modem and router indicator lights are normal.

 

[electron]

Do you get a time out when you try this from a hardwired computer, or just wireless?

 

[JohnBullard]

hardwired

The next time i'll also try wireless as well.

 

[electron]

Just to confirm, the IP address of that machine is hardcoded, correct?