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MrSleepy
04-09-2010, 05:07 PM
At my home I have a standard network...cable modem ->broadband router -> to 4 pcs.

Until recently we had 4 big box pcs that stayed where they where...but swmbo and I are moving to laptops...and the big boxes being relegated to more important mach3 duties.

My ISP only allows me one IP address (fairly standard)..so cable modem -> WAN -broadband Router- ->LAN to PCs.
The cable modem will communicate with only one MAC address, and will issue only one IP address via DHCP...the router is the single device to which the cable modem issues the single IP address, and the other PCs communicate with the internet via a process of Network Address Translation (NAT) performed by the router.

the question..............................

If I have had my laptop network connected and working to the router LAN port RJ45 in the front room and unplug it..replacing it with swmbo work laptop

I will get the "connection not available" messages as expected..(and if I reconnect mine it works fine again)
I have tried to use the XPs ipconfig /release and ipconfig /renew (and gui-Network Connections->repair) to get the routers internal DHCP server to release the old settings and allow the newly connected laptop to work with no joy.

Power cycling the router does allow the Laptops to be swapped.


How can I swap the laptops without power cycling the router?..

Notes..

Can't use wireless due to existing noise and the amount on networks already in the area..Its the reason I went back to cable.(and safer with the new laws affecting the UK).
Micro$oft or other ICSs are not an option.


Thanks Rob.
edits in red

RB211
04-09-2010, 05:12 PM
Does your router have multiple LAN ports? Plug each computer into its own port, if not, buy a hub or a switch.

MrSleepy
04-09-2010, 05:19 PM
Does your router have multiple LAN ports? Plug each computer into its own port, if not, buy a hub or a switch.
Yes..the router is a belkin broadband with 4 LAN ports/switches and print server.. all used...Its the front room rj45 wall connection that we plug/unplug to..

Cheers Rob

macona
04-09-2010, 05:27 PM
When you have a router connected to the cable modem the ISP will only see one IP address being use. Your router should have DHCP on internally and you can connect as many computers at once as you want. The ISP will never know.

You should use wireless.

I use a WRT54GL with Tomato firmware installed.

DFMiller
04-09-2010, 05:28 PM
Why don't you get a router between your Cable modem and PC's that is a DHCP client to the Cable box and a DHCP server to PC's then you should not have the problem you are having. That's what I have been doing here for years. I am running a Linksys Cable/DSL Router here that seems to work well. It has 5 PC's plus 3 wireless access ports. It seems ot work well for me.
Dave

Evan
04-09-2010, 06:31 PM
It is probably an IP conflict where the wife's laptop is being assigned the IP you had. When you connect back up your laptop tries to use it's existing IP and that doesn't work. You can get around it by manually assigning different fixed IP addresses in the Network Properties <TCPIP> panel on each laptop. They will not request DHCP from the router but will declare what address they already have.

bob_s
04-09-2010, 07:27 PM
Have you configured all of the machines to belong to the same workgroup??

If so you must keep in mind that a workgroup is only allowed a single MASTERBROWSER - that is the machine that keeps track of which machines are connected to the network.

It takes a significant amount of time for the masterbrowser to update the workgroup information.

This can be complicated by the fact that you may unknowingly disconnect the masterbrowser itself.

The act of connecting a "new" workgroup member may trigger the resetting of which machine is the masterbrowser, this too will take significant time as communication within the workgroup is required to collect all of the requisite information. GOD forbid that you have a VISTA-64 machine associated with the same workgroup as your XP based machines ---- DAMHIK!!!!!!!

If you have reached the port limit of your router with the number of household machines, it is time to investigate setting up your own PROXY, or internal GATEWAY. Simply put, a computer with two ethernet cards running software which allows machines connected to the internal IP branch to communicate with the external IP branch, that is connected to the router.

MrSleepy
04-10-2010, 07:50 AM
It is probably an IP conflict where the wife's laptop is being assigned the IP you had.

Hi Evan

The problem is the Belkin broadband router..its holding on to the MAC address of which ever PC etc that first requests a new DHCP lease.
Thats why power cycling works.Although an ipconfig release /renew of DHCP should work but doesnt..could be a router issue ..don't know.

I've solved the problem (of swapping PCs/Laptops) with a slight kludge , but as its only one web surfing connection in the front room it will suffice.

By using an ethernet to USB connector (ETH->USB) I had lying about..as you do...The router can hold the MAC of the ETH->USB and process DHCP for it..and the laptops connect via usb with no issues.

thanks anyway

Rob

MrSleepy
04-10-2010, 08:01 AM
For those who suggested wireless..

I know its easier and this issue would never have arisen ..but the UK Gvmt has brought in some new draconian laws.

If someone breaks into my wireless network using the widely available FBI cracking kit or suchlike...and downloads a bucket full of kiddi porn.

Then its up to me to prove I'm not the guilty party.

http://boingboing.net/2009/11/20/britains-new-interne.html

So as I've had my own subnet for some time with rj45 throughout..I have gone back to cat5 cable based... the linksys wireless router was a festival of dropouts (prolly caused by the nearby RADAR station)..and with cat5 I dont get dropouts.

Rob

Evan
04-10-2010, 09:13 AM
The problem is the Belkin broadband router..its holding on to the MAC address of which ever PC etc that first requests a new DHCP lease.
Thats why power cycling works.Although an ipconfig release /renew of DHCP should work but doesnt..could be a router issue ..don't know.


Assigning fixed IP addresses will fix that issue.

fahnoe
04-10-2010, 09:51 AM
Rob,

This sounds a little bit like the Belkin may have a security feature enabled which is attempting to fix MAC addresses to specific ports. I don't have experience with Belkins, but would suggest you look at your management interface and see if there is an option that can be turned off. Features like this are something that would be more commonly available on larger business class products, so it seems odd on a home product like Belkin tends to offer.

--Larry