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Something weird is going on my home...

S

soamz

macrumors 6502a
Original poster
Jun 20, 2010
705
8
Orissa, India
Here is my setup..
45073_10150232580610262_875760261_14264850_6305264_n.jpg


The BSNL modem's LAN 1 is connected to the iMac.

It all works fine.

But as soon as I switch on any of the windows PC on the both sides, the modem gets crazy and the whole line gets unstable.
Like the internet starts going on and off continuously.


I dont understand, what is the reason.
Is windows system emitting some radio signal or seducing the modem to go crazy ?

Dont know, what is it..
Anyone ?
 
how do you connect all 3 machine to the modem? do you have a switch? or a router or what??
 
The modem has a 4 ethernet ports.
I directly connect all the ethernet ports of the PCs and iMac and macbook pro to the modem.
 
I have no idea how much experience you have in networking, I was only trying to help! No need for the sarcasm! Try following Wheaton's Law.
 
You've most probably checked this already but I'll throw it in anyway: maybe your Windows machines are infected with a virus or worm and what you're seeing is a data storm or DoS attack? Hard to imagine that both machine's network cards are bad at the same time. You've also already indicated that all machines are on the correct subnet and are not colliding with the same addresses...

Strange
 
is the link speed for everything set for auto?
If you have a mismatch it can cause collisions.

check for virus's, since both machines do it I suspect a virus.

install a firewall (something like little snitch but for windows) to help block outgoing connections so you can try and track down what is going on.

boot into safemode with network and see if the problem still exists.
 
Here's a bonehead move to check for:

When the computers were being hooked up, did both ends of one cable get plugged into the router? I did that once, and I can say that really pissed off the router.

Barring any hardware issues, is there an IP conflict? Looking at the activity lights on the network ports should allow the OP to check if the traffic is heavy.
 
No virus..
And its not that, after the PC gets switched on, the modem goes.

Im saying, as soon as I switch on the PC's power button, the modem immediately goes off and then the unstable story starts, till I power off any of the PCs .

Cant that be a electricity issue ?

Actually, I have just one socket in this room.

And I have connected everything to this one socket.
Do you think, its overloading it doing some voltage drop ?
 
Do all the lights on your modem go off when you power your PC on? If so it sounds like a power issue somewhere. You might be drawing too much power from that outlet. Try turning your Macs off then powering on the PC. If it still happens it might be something other than power. I'm not an expert in electricity but I'd think if you were overdrawing power you'd blow a fuse or trip a breaker.
 
Does the modem act this way if the PC is on but the other Macs are off? It could also be the modem for some reason not handling the traffic from all the computers. Since you said the modem has 4 ethernet ports on it I assume you have a DSL modem with a router built in. Something could be messed with the router portion. Have you had this setup working for a while and this just started happening? If it just started happening recently I would call your ISP and have them look at your modem diagnostics as this problem is occurring. It could be an issue with the modem possibly.
 
soamz said:
Actually, I have just one socket in this room.

And I have connected everything to this one socket.
Click to expand...
That's quite a bit of power to be pulling out of one outlet. DSL can be severely effected by electronic interference.

Some troubleshooting steps to take:

  • Make sure that the phone line that goes into your DSL modem is separated from the power cords (just don't run them in one bundle together, can cause interference).
  • On your modem (that's also your router), I would recommend setting up a DHCP reservation table. That way, no matter what items are on or off, they will always have the same IP address. Without a reservation table, it's first come, first served as far as the IP addresses go. If your computers are getting different addresses, it can make sharing and such harder (and can cause IP conflicts if a newly powered device pulls an IP that's already in use).
  • It looks as if you have 2 PCs. Is the problem only with one or with both? If only one is on, is the problem still there? Might be a bad NIC in one of the PCs.
  • Your DSL modem/router probably has a log in it. Check into what's going on in the log. It should tell you what sort of errors are knocking out the DSL sync.
 
Hi..
One thing I noticed just now.

When PCs are switched on, the modem doesnt go crazy.

But as soon as I connect the rj-45 cables to the modem's ports, the link goes off and on.
So, starts the blunder.

So, is there something conflicting or what ?

Im totally blank, damn it.

And dont think power is a problem, since it works 10001% perfect, when just the imac is on.
As soon as I switch on any of the windows system, it goes crazy.
 
try a cheap 4 port switch between your computers and the modem see if that works

what are the 4 eathernet sockets labelled?

so the powerstays on all the time on everything just the dsl disconnects?
 
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