LAN problem

NoQuarter

Hi folks,

Have a LAN set up in my house (all windows XP) and all running through a switch. So today we got a new desktop computer which replaced the old one in out front room.

so i just plugged out the network cable out of the old desktop and into th new one and it wont work. Im gettin "limited or no connectivity".

All computers are set to obtain IP address automatically. Ive compared settings and they all seem the same. So im pretty stumped!

Ideas?

Cheers.

Random

login to the switch and check the dhcp range?

NoQuarter

Random wrote: »

login to the switch and check the dhcp range?

Hi random,

I dont think i can log into it, its just a small 8 port switch, just like one of these little fellas: http://di1.shopping.com/images1/pi/ac/16/95/27948143-260x260-0-0_Linksys+KIT+LINKSYS+8PORT+SWITCH+10+100.jpg


The thing that baffles me is that the old desktop works just fine so it must be a setting on the new desktop thats the problem?

Random

i'd have thought you could login to all home switches but i'm not expert on it.

have you tried taking one of the existing cables from one of the working pcs and trying it in the pc that's not working to rule out connection issues?

NoQuarter

Yeah ive tested the connection issues and the working computers work fine with the desktops cable and the desktop does not work from the laptops cables!

bonzodog2

Did you try:
restarting the pc from cold
disable/enable the NIC
ipconfig /all (post results)
reseat cable (pull in and out)
power-cycle the switch
check device manager
reseat NIC if its a PCI (unlikely these days)

NoQuarter

bonzodog2 wrote: »

Did you try:
restarting the pc from cold
disable/enable the NIC
ipconfig /all (post results)
reseat cable (pull in and out)
power-cycle the switch
check device manager
reseat NIC if its a PCI (unlikely these days)

Hi Bonzodog,

Ive restarted the PC from cold.

Im not sure what a NIC is!

Cable has been reseated.

Pulled the power cable from the switch a few times.

Havent checked device manager?

____________________________________________

IPCONFIG:

Working laptop:



Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\Documents and Settings\user>ipconfig /all

Windows IP Configuration

Host Name . . . . . . . . . . . . : STUART
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Unknown
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : chello.ie

Ethernet adapter Wireless Network Connection:

Media State . . . . . . . . . . . : Media disconnected
Description . . . . . . . . . . . : Intel(R) PRO/Wireless 3945ABG Networ
k Connection
Physical Address. . . . . . . . . : 00-1B-77-5D-B4-F1

Ethernet adapter Local Area Connection 2:

Connection-specific DNS Suffix . : chello.ie
Description . . . . . . . . . . . : Broadcom NetXtreme Gigabit Ethernet
Physical Address. . . . . . . . . : 00-1B-38-39-B0-B8
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 79.97.50.188
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 79.97.50.1
DHCP Server . . . . . . . . . . . : 10.52.10.1
DNS Servers . . . . . . . . . . . : 89.101.160.4
89.101.160.5
Lease Obtained. . . . . . . . . . : 25 April 2010 15:16:46
Lease Expires . . . . . . . . . . : 28 April 2010 06:38:27

C:\Documents and Settings\user>


Broken Desktop:


Windows IP Configuration

Host Name . . . . . . . . . . . . : DOWNSTAIRS
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Unknown
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No


Ethernet adapter Local Area Connection 2:


Physical Address. . . . . . . . . : 00-1B-38-39-B0-B8
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 169.254.169.192 (i assume this is the lad i bought the desktop off's IP address)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . :

__________________________________________

Dardania

what's happening is you are plugging your working laptop directly into the UPC modem, through the switch - with no router in between. The modem is setup in such a way to give a public IP address to the first device that gets connected to it, which works fine if there is only one device going to ever use the internet, however when you plug a second device into the modem, the modem wont give out a second IP address.

The solution here is to put some sort of router between the modem and your internal network, something like any of these: http://www.komplett.ie/Komplett/catalog/ZKB_01COM/18_NETWORK/14_ROUTER/default.aspx - it will take the public IP address, and assign it to the public interface of the router, andf then assign internal IP addresses to any internal devices (like your laptop or desktop), and allow them to route out to the internet using network address translation.

NoQuarter

Dardania wrote: »

what's happening is you are plugging your working laptop directly into the UPC modem, through the switch - with no router in between. The modem is setup in such a way to give a public IP address to the first device that gets connected to it, which works fine if there is only one device going to ever use the internet, however when you plug a second device into the modem, the modem wont give out a second IP address.

The solution here is to put some sort of router between the modem and your internal network, something like any of these: http://www.komplett.ie/Komplett/catalog/ZKB_01COM/18_NETWORK/14_ROUTER/default.aspx - it will take the public IP address, and assign it to the public interface of the router, andf then assign internal IP addresses to any internal devices (like your laptop or desktop), and allow them to route out to the internet using network address translation.

Thanks for that Dardania, the only thing is the network has been running fine for months now just the way it is, internal IP addresses seem to have been no problem. There has always been 3 computers (2 laptops and one desktop). All i have done is simply change desktop, so I dont think lack of a router is the problem!

NoQuarter

There seems to be a "control suite" for the network card installed on the desktop and when i go into that it has the 169.254 IP address on it and it seems unchangeable.

Would that program be overriding the system so that it cant get its own IP address perhaps?

Dardania

addresses in the 169 range are automatically self-assigned by a computer when the computer can't get an IP from a DHCP server - the UPC modem isn't giving out IP addresses because it's after giving out the 1 IP it can to the working laptop - have a look here: http://en.wikipedia.org/wiki/Private_network#Link-local_addresses

The possible reason things worked for you in the past could be because you used each PC separately, the first time you switched them on?

Either way - you need a router - no two ways about it!

As a temp fix - you could unplug the other PCs from the switch, power off and on the modem, then plug the new desktop in - but that will preclude the use of the laptop at the same time.. see here also: http://service.upc.ie/service/?cid=138

NoQuarter

Ok thanks! the other strange thing is that both laptops work at the same time still though!

Dardania

What IP addresses do they get? Maybe UPC are allowing you two?

NoQuarter

The 2nd laptops IP address is 79.97.50.67 while my working laptop is 79.97.50.188.

Perhaps i should plug in the old desktop that was working and see what its IP address is.

NoQuarter

Just an update: I plugged in the original desktop that worked fine before and got all its settings, put them into the new desktop and now it seems to connect fine but it wont go onto the internet! The browser just cant seem to get out!

Any ideas?

johnciall

your being assigened more tha 1 Public IP by the UPC modem, to be honest having your home network connected directly to the internet is genreally a bad idea and, as you've already seen, it's unstable. better off paying the few quid for a router and having peace of mind

NoQuarter

Thanks john,

I have it working now, its not unstable as regards of connectivity or speed now that its working. I am however concerned about security.

Is there anything i can do for the moment to secure it? Buying a router is not an option for the moment. Will the network still work with file and print sharing turned off with regard to browsing the internet? Files do not need to be shared between the computers.

Dardania

make sure you firewall is active - that is all you can do.

but seriously - buy a router: http://www.adverts.ie/showcat.php?cat=all&si=router&sort=1