Home networking - can't create a LAN

Flippy_D · Tue 09/01/2007 21:36:37

Hey guys, I'm trying to network my computer with my Dad's laptop, but the LAN isn't being recognised. Currently I'm using this setup:

PC -> Patch cable -> RJ45 reverse cord coupler -> Patch cable -> Ethernet card -> Laptop.

I know that I *can* LAN these two because I have before. Can anyone tell me what might be wrong? Is the coupler the right one?

I can probably answer any questions you need answering.

Thanks in advance =)

Edit: Ah, righto. Thanks CJ.

Khris · Tue 09/01/2007 23:18:36

The most important questions:
What are the operating systems of the two computers?
Are there any firewall programs running on any of the two?
Which IP addresses and subnet masks did you set up?
Can you ping the other PC?

Chicky · Tue 09/01/2007 23:20:56

crossover from pc - laptop network card surely?

Flippy_D · Tue 09/01/2007 23:24:56

Quote from: KhrisMUC on Tue 09/01/2007 23:18:36
The most important questions:
What are the operating systems of the two computers?
XP, both.

Are there any firewall programs running on any of the two?
My computer has Norton Business Edition, but lowering it doesn't help.

Which IP addresses and subnet masks did you set up?
I didn't... as far as both computers are concerned, the LAN connection is 'unplugged'.

Can you ping the other PC?
See above.

Quotecrossover from pc - laptop network card surely?

I'm not sure. It's worked before. I'm using a plug and play card.

LGM · Wed 10/01/2007 02:47:35

I always thought you needed a hub to network two computers...

Flippy_D · Wed 10/01/2007 02:48:47

Well, it's worked previously. It's just a method of connecting my Dad's laptop to my PC so we can share the internet connection. Nothing greater than that.

Khris · Wed 10/01/2007 12:17:39

Ok, so the whole setup is already failing on hardware level.
If it has worked before, the only thing I can think of is a faulty nic driver or an IRQ conflict or something like that.
Have you tested the network cards separately?

(If this is going to be permanent, why don't you buy a router? Just an idea. I know, they aren't that cheap yet, but I find dialing in/up to be annoying anyway.)

Oneway · Wed 10/01/2007 16:48:22

Another thing to check if both the network card have an ip address in the same range. If there isn't a device that gives out local IP addresses (called a DHCP server) then you'll have to configure both cards manually.

TheYak · Fri 12/01/2007 05:23:05

Rather than software mystery, I'm suspecting your setup.

-Why are you using a coupler? For the added range only?

-If you're using two patch cables with a reverse coupler, you've connected them to a device that reverses the pin order when the patch cable (aka crossover cable) has pins 1&2 going to 3&6 and vice versa.

-If all the cording is right, strand wire for CAT-5 is only rated for about 10 feet. For longer distances you'd want solid-core, so the cords + coupler might be too much resistance for the connection to work properly.

Eliminate the problem cords first of all. Connect the laptop ethernet to PC ethernet with a single patch cable.

(A brief educational note for LGM - you can use a hub - known as infrastructure networking - using straight-through cables. You can also network in ad-hoc mode which uses the crossover cabling, in a way like making each network card a client/host port)

Flippy_D · Fri 12/01/2007 05:26:55

The coupler making the two patches into crossover is intentional - It's meant to be crossover, isn't it?

I'm discounting distance for two reasons:
1) It's worked before.
2) Using just one cord makes no difference.

Once I can get the two systems linked via the ethernet cable I can do the rest. It's just that they don't seem to want to link up.

LGM · Fri 12/01/2007 06:11:53

ad-hoc, yes. Duh. I should've known that. I guess I asked that more because I didn't know why he was doing it that way, but each to his own I guess. Good luck, Flip.

TheYak · Fri 12/01/2007 08:24:58

Patch cables are crossover cables. You've got two options, crossover/patch for ad-hoc and straight-through for infrastructure networking. Sorry, didn't catch on that you were talking about a reverse - crossover-type coupler versus a reverse pin-out, so the coupling is just redundant.

Theory about solution... reverse the connections on one of the cables. It wouldn't change anything wiring-wise, but if there's a difference in conductivity it might.

Was playing with a diagram to make sure I was thinking correctly...

And these are cables you'd previously used to network? You know that they're both patch cables? Don't suppose you've got a multimeter or RJ45 tester handy?

I can see the network sharing being problematic with incorrectly-configured IPs or missing protocols or something, but
(I'm assuming WinXP here) it should show a connection, just have problems with file transfers or internet sharing. If it sees no connection at all, I'm still thinking cabling or bad/conflicted cards versus network settings.

Flippy_D · Fri 12/01/2007 16:09:45

Thanks, Yak.

If I get to try that in the two days before I go back to Uni, I'll let you know what's what. Otherwise I'll have to bookmark this and return some other day =(

But I appreciate all the help thus far =)

Even if it's somewhat hard to follow >_>