Hi,
Thanks ahead, for anyone who'd try to help me figuring out what's going on with my computer.
I have this problem over the past two years! But it somehow solved and occur by itself..
Anyway here it is:

I have my two computer, one desktop and one laptop, connected through a switching hub(8 ports), also have an adsl modem connected to that switch, just as a modem, not router.
Now, from time to time, suddently the network connection, just 'disappear'! And like I mentioned above, the same way it disappeared that's how it gets fixed and work as usual.
BTW, I'm currently at this weird situation, where it's not working.
Now, after all this time, I think I can focus my problem on my desktop computer, and this is why:
When the problem occur, when pinging the modem through the desktop computer, I get no response what so ever.
But, if I do the same thing through the laptop I get a response from the modem.
Now, if I disconnect the modem from the switch and connect it to my dekstop comp regulary, it pings well.. but through the switch it won't respond.
BUT like I said, only in times where it 'decides' not to work, other times where it's working fine, I get response when pinging through the switch on the desktop comp...

So.. what's going on here?
All the cables I'm using are fine,
I've tried changing ports on the switch, but all are fine too,
I have norton firewall only on the laptop, but it worked well before, and even when I turen if off, when the problem occur it's not solving anything.
So, the question is what can cause my other computer(desktop) to block connection through my switch, but other time work fine?

PLEEAASE help me,
I'm going crazy here.
Thanks ahead,
An3c.

First I have never seen a software problem fix itself. So you probably have some bad hardware or a virus. If you haven't already done so, check for viruses.

If you are clean then you have a hardware problem. I would suspect a hub or network card. Start by condsidering the environment. High temperature or high humidity can effect the performance of some electronics. Intermittent problems are a bear to solve.The easiest way is by substitution.

You need to talk to your DSL carrier about this. But I suspect the problem may be in not using a router.

Most broadband carriers provide one IP address to their modem. Since your hub doesn't provide DHCP services, the only way it will work is if you can get another IP from the modem. Therefore, the first PC that powers up will get the IP and the Internet access and the other will be blocked. Now its possible that the carrier doesn't restrict IPs through the modem or that they only do so sometimes.

The simple answer here is to get a broadband router. There are several available for under $50. I'm sure that one will solve your problem.

If this set up has never worked properly since it was installed (i.e. you have always had intermitent connectivity problems), I would suggest that it is due to the fact you have the modem connected into the switch, and not directly connected to a PC via the network interface.

Check out this URL http://www.dslreports.com/pictures#3 . You have your network setup as "DSL modem in Bridge configuration". If you are not paying for extra IP addresses for your network from your ISP, this would suggest why it is failing.

As ScottGem suggests you should be using a router for this type of setup. I would be very surprised if it was a problem with your DSL connection to your ISP.

Don't know what's near you, but Compusa has a 54G Motorolla Wireless router for $7.99 for the next 4 days. You can often find a router for less than $20. This, as someone else stated, is most likely your problem.

But, you're getting it all wrong.
It's not related to internet connection, that is not my problem. Like I mentioned, I'm not trying to connect to the internet with both computers at the same time as it's not a router. Simply a network of two comps and a modem, which is connected to the switch as well, allowing me to connect the internet from either one of the comps, but again, not at the same time.

I guess I could describe my problem better, without mentioning the network, but I did mentioned it, just to show you that when the modem is connected through the switch, one computer is having intermittent problem of not getting a response from the modem, while the second computer that is connected exactly the same way, has never had this kind of problem, meaning the switch is okay.. (or isn't it?)

Like walt17 mentioned above, I think it must be the network card on the desktop computer(the one having the problem). Albeit it works fine when the modem is connected directly to it, maybe(probably) the switch has an internal software(or somehting) that conflicts with the card.

If I'll go buy a router, that's not promising me a success.. the router also acts as a switch, and the modem would still need to be connected to it.. so beside the fact that now I can share internet connection, with both comps, it's still the same structure.

Anyway, I'll replace the netwrok card first, if that won't work, buying a new switch would be a dumb thing to do, so I'll buy a router, if that won't help either, I think there's something wrong with my mobo, or something with the pci slots.

Thanks all for your help,
Appreciated.

Edit:
BTW.I'm from Israel, the cheapest router that I found, (wire, not wireless), costs $60 w/o s&h. But again, this is really not the issue or a problem.. just want to be sure I'm replacing the faulty part.

Ok, it wasn't clear that you were only trying to connect one PC at a time. With that being the case, and the problem only occurs with one PC, then yes, I would consider the NIC a problem. Can you swap NICs between the 2 PCs and see if that cures it?

I can't swap NICs, as one computer is a desktop and the other is a laptop.
But, I hope I'll get a new card today or tomorrow latest.
Then, of course, I'll post the outcome.


Thank you again, for your help.
An3c.

I hope it works out for you. If not, I know you said the cables are fine but I would double check them. No offense if you already did. Also, some modems can get fixed to certain mac addresses so unless you 'restart' the modem, switch, and PC when you switch the connection you can't be sure. What the router will do for you is give every device on the network a separate IP address. With both of your computers on the switch, the modem is going to give an IP to one of them. Who knows what coincidences are happening while you are using the PC but maybe something is interfering because of DHCP renewal or other timed events. If you are using Modem->Switch->PC, and you've restarted every device, how long does the connection last if you can connect at all? Make sure the laptop or any other device is not hooked into the switch with the PC.

Good luck, And like I said I hope the new network card solves your problem.

I bought a new NIC, was about to install it, but told myself to take -phr0ze- comment and TRIPLE check the cables.
And what do you know,. till this moment, It works!
I can not believe it turned out to be a faulty cable, causing all the problems!

So, I feel like a real dumba$$, but to my defence, like I mentioned above, the first thing I did when the problem first appeared, was to check the cables, and at that time it worked flawlessly(? ) when connected to other devices..

Well lets hope it is the problem, and I'll see if I can get refunded for the new NIC :p
Anyway, I want to thank this great Froum, and of course, all of you guys, for helping me clearing up this issue.

Till the next problem, (meanwhile I'll stay as a dedicated reader ;) )
An3c.

THANkS AGAIN!

Glad you got it working. Might want to keep that NIC as a spare just in case. They aren't expensive.