Forums > Help! > ipconfig release help?

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SpitFireGOLD Member
Mand's Girl....and The Not So Shy One
2,723 posts
Location: Calgary, Alberta Canada


Posted:
OK, not poi related, but perhaps someone who knows a thing or two can help me with my network issue?

I can't get my PC to release old IP addresses. The ipconfig /release command doesn't work, and forget the ipconfig /renew command. I've got a new network card, but I have a bad feeling my poor old beast of a machine may be hozed. Ideas? Please send info to me in a PM. I won't get to check it until tomorrow evening Calgary time.

Thanks in advance!

Solitude sometimes speaks to you, and you should listen.


Bender_the_OffenderGOLD Member
still can't believe it's not butter
6,978 posts
Location: Melbourne, Australia


Posted:
re.boot!

Laugh Often, Smile Much, Post lolcats Always


flidBRONZE Member
Carpal \'Tunnel
3,136 posts
Location: Warwickshire, United Kingdom


Posted:
depends totally what version of windows you're using, and whether you're using dhcp or assigning the address manually

polaritySILVER Member
veteran
1,228 posts
Location: on the wrong planet, United Kingdom


Posted:
If it's XP, then yes, windows refuses to let go of an IP address that's assigned to old adapters, even if they're no longer in the computer.

When you click on Apply or OK when trying to set that IP to another adapter, you should see a box that says that the IP is already in use. One of selections will send you back to change the IP the other will just use the one you've given, although it doesn't make this obvious, or mention that it won't cause any problems. You'll have to do this each time you want to reassign that IP on that computer.

There are two ways to stop this. The first is to uninstall the old card in device manager before you remove it. The other involves hacking the registry to remove the old hardware settings, although you have to be sure you have the right place.

You aren't thinking or really existing unless you're willing to risk even your own sanity in the judgment of your existence.

Green peppers, lime pickle and whole-grain mustard = best sandwich filling.


SpitFireGOLD Member
Mand's Girl....and The Not So Shy One
2,723 posts
Location: Calgary, Alberta Canada


Posted:
Since it's a cable modem, I'm using DHCP. I'm also using XP.

I've not had the problem on my laptop, which is also XP, and used on the same networks.

I've already uninstalled the old card (didn't uninstall in device manager first).

Hacking into the registry...oi...I'm a bit nervous about that...I'd need a step by step on that one.

Solitude sometimes speaks to you, and you should listen.


polaritySILVER Member
veteran
1,228 posts
Location: on the wrong planet, United Kingdom


Posted:
What DHCP does is associate the MAC address of your network card (which is supposedly unique for that hardware) with a free IP address, for a period of time. If you change the network adapter then you change the MAC address, and the DHCP server in the cable modem won't give you the old IP, as it's reserved for the old adapter, until the lease time expires.

The only way to fix this is change the lease time in the Cable Modem settings (if it's there at all), so that the lease time is shorter, which might result in IP addresses getting swapped around between computers, or use fixed IPs.

If all of your computers have fixed IPs you'll need to give them individual addresses, and three further IP settings for subnet mask (usually 255.255.255.0), gateway/default route (usually of the form 192.168.0.1), and DNS server (usually the same as the default route).

If you look at the network status for a DHCP XP system, then it should have values for all those, you just need to set them manually, and come up with some new IP addresses that don't have a lease on them.

You aren't thinking or really existing unless you're willing to risk even your own sanity in the judgment of your existence.

Green peppers, lime pickle and whole-grain mustard = best sandwich filling.


mechBRONZE Member
Carpal \'Tunnel
6,207 posts
Location: "In your ear", United Kingdom


Posted:
excuse me for stating the obvious, but it its a new card, new mac address, hence new ip.

Windows should have leased out a new ip, allowing the card to connect.

i cant be bothered to type anymore, as this will end up in a techie argument which i cant be bothered with

spitfire - good luck

Step (el-nombrie)


flidBRONZE Member
Carpal \'Tunnel
3,136 posts
Location: Warwickshire, United Kingdom


Posted:
Written by: mech

excuse me for stating the obvious, but it its a new card, new mac address, hence new ip.

Windows should have leased out a new ip, allowing the card to connect.




That's quite a broad statement, which totally depends on how the dhcp server is set up.

surreal.blissMember
1 post

Posted:
if you have dhcp like you stated... then its not windows that binds the mac address to the network card... its the dhcp client on your isp's side... you have 2 options...

1:

either put the network card back in the computer and release the ip, then exit the cmd prompt unplug the modem from the power source and turn off the pc... leave both off for about a minute then start the modem first, followed by the pc... of course you would also have to put the new card back in while the pc and modem are off.

2:

unplug the modem from the power source for about a half an hour... this will reset the mac in the isp side dhcp...



however there is another thing that might be in your network that you didnt mention but you made clear might be there...

i guess you have a router because you said the other computer works fine...

if this is so... include the router as one of the things to remove power from in both steps.





(thank you verizon dsl for letting me work in your tech support center)

polaritySILVER Member
veteran
1,228 posts
Location: on the wrong planet, United Kingdom


Posted:
I hate putting people down but that is just so wrong. There are a surprisingly large number of people on this list with a very high level of computer experience (nearly 20 years at the programming level in my case), so it's probably best not to jump into the help section just after joining to answer computer stuff. Don't let it get you down. If you did tech support you've got people skills I don't, and you probably have a better social life wink



Written by:

if you have dhcp like you stated... then its not windows that binds the mac address to the network card... its the dhcp client on your isp's side




Might actually make sense if it said:

Written by:

if you have dhcp like you stated... then its not windows that gives the IP address to the network card... its the dhcp server on your modem/router




This:

Written by:

1:
either put the network card back in the computer and release the ip, then exit the cmd prompt unplug the modem from the power source and turn off the pc... leave both off for about a minute then start the modem first, followed by the pc... of course you would also have to put the new card back in while the pc and modem are off.

2:
unplug the modem from the power source for about a half an hour... this will reset the mac in the isp side dhcp...





makes some sense. You can only get the modem/router's dhcp server to release the IP it's given to the network card in the XP system, using that network card.

Turning things off dosen't reset too much modern hardware, as the settings are all stored in non-volatile memory. They should have a reset button on them, or an option in the settings (usually accessed through a web browser) to purge the DHCP lease tables, (it may just be to reset everything though).

So you have 3 options:

1: Put the old network card in, connect to the modem/router with that network card and tell it to release the IP.

2. wait for the lease to expire. This could take days depending on what the lease time is.

3. reset whatever part of the modem/router handles the DHCP leases. If it's an old modem then turning it off may work, otherwise it should have a hardware reset switch on it, or options in the settings to clear data. If you do any of these you may need to reset usernames and passwords that the modem uses to connect to your ISP. If you're lucky then the DHCP settings can be cleared seperately from the other settings in the control panel. That's if it's the kind of modem that allows you to change settings through a web browser.


If you change the network card it will have a different MAC address, and the modem/router's DHCP server will refuse to release or renew the IP address when you send that request with a different network card. This is because it could be an attempt by someone else on the network to steal your IP address and intercept data (more likely in huge corporate networks, but the hardware has to do the same thing for home networks).

The other computer is working fine because you haven't changed the network card in it (and hence the MAC address that is used to reserve it's IP)

You aren't thinking or really existing unless you're willing to risk even your own sanity in the judgment of your existence.

Green peppers, lime pickle and whole-grain mustard = best sandwich filling.


SpitFireGOLD Member
Mand's Girl....and The Not So Shy One
2,723 posts
Location: Calgary, Alberta Canada


Posted:
Well, for a bit more history....

The problem started back in Houston when we moved from one place to another in June. A friend of mine who does networking stuff for a living came over, and we went through the ipconfig release routine a few times. He tried a few other things (getting the IP address from the laptop, releasing the address, and then trying the desktop I think...along with other things I can't recall.)

When nothing worked, he said it was probably the network card. I didn't pursue the problem then because I was busy.

I'm not using a router right now....I have a new one to use once I get both machines running.

The IP address that the desktop is holding is the same it was holding in Houston.

So before the move in June, the desktop worked great. After the move in June...nothing. (with the old card)

Now...nothing....

I tried releasing the IP address with the old card in up here in Canada, and nothing. I'll probably put it back in, and try again.

I may put the new card in a different slot, just in case.

Thanks for the advice folks. If you think of anything else, just let me know.

Solitude sometimes speaks to you, and you should listen.



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