IP conflict (DHCP assigned) when hibernating on home network

[David D.]

I have been researching postings about IP conflicts using DHCP. Although
there are tons of such postings, most have to do with mixing DHCP with
static IPs, or with split-second timing problems, or with clearing IP
conflicts after they have occurred.



I suspect that my IP conflicts are related to leases expiring and IP
addresses being reassigned while the original lessee is hibernating.



This is a home network with a cable-modem and a router that serves as my
DHCP server. There are no static IP addresses in the DHCP IP pool range.
Computers in my house are typically hibernated rather than shut down, so
that work in progress can be left open, and so that the computers power on
faster.



I have had intermittent IP conflicts with my old, wired Linksys router. I
eliminated that problem by setting the IP lease length to three years.



My new router is a wireless Netgear, with both wired ports and wireless
connections. This may complicate things a little for two reasons: (1) the
Netgear router does not have a setting to allow one to change the IP lease
length, and the lease length is pretty short, and (2) the same computer
might have one wireless connection and one wired connection. I prefer to
keep wireless disabled for increased security and higher bandwidth, but it
is often convenient to use wireless.



However, the problem still occurred with the old, wired-only router.



My network is a mix of Windows XP, Windows 2000, and Linux-based appliances
(a pocket print-server appliance and a TiVo).



Will an expired IP lease be discovered on waking from hibernation? Could
hibernation be the problem? Or is there some other issue that I should be
looking at?



- David

 

[Glen]

Go into your router's setup and see if you can reserve each IP address for
each computer. Tell the router the proffered IP for each computer. Usually
done via the MAC code. It should be fairly obvious but if you need more help
repost with the make model of router.

 

[David D.]

Thanks, Glen.

I will take a look. I know that my router (Netgear WGR614) offers
MAC-based security. I will look to see if it also has preferred IP by MAC
address.

I set up the router with WPA security. I do not know if I need to turn
off WPA in order to use MAC security, but I will explore the related admin
menus and let you know how I make out.

I would still be interested in knowing the cause of my IP conflicts.
Netgear tech support told me that I cannot get IP conflicts by hibernating
computers, that the router will handle everything correctly. I am not
convinced that that is the case. For example, what happens to Browser
sessions that span the hibernation? I suggested a firmware upgrade to
allow one to set the IP lease duration, in order to solve the IP conflict
problem via a long lease. Their response was essentially that there is no
problem.

- David
~~~~~~~~~~~~~~~~~~~~~~

 

[FedUp]

On Thu, 13 Jul 2006 14:07:49 -0400, David D. wrote:

Will an expired IP lease be discovered on waking from hibernation? Could
hibernation be the problem? Or is there some other issue that I should be
looking at?



- David

In your power management settings ensure that your NIC is not powered off
when your computer goes into hibernation. ll my computers retain network
connectivity even when in hibernation mode.

 

[Glen]

When you start a computer it gets assigned an IP, eg 192.168.0.2 from the
router. When it hibernates it effectively shuts down. Windows as it was
running is stored in the hibernating file. When another computer on the
network starts up, the router, thinking the previous IP is now free (because
the hibernating computer is effectively shut down) assignees 192.168.0.2 to
the computer just starting up. When the hibernating computer wakes up it
already thinks it has the right to use 192.168.0.2 because as far as its
concerned it was given to it and it hasn't given it up. Hence the conflict.

 

[David D.]

help repost with the make model of router.

Glen,

Thanks for the tip about the router setting for reserved IP address by
MAC address.

The Netgear WGR614's configuration menus are well designed. I did not
even have to type in the MAC, IP and computer names. They were prefilled
for me. All I needed to do was to click a radio button.

David

 

[Michel Merlin]

Most Hibernation problems in XP were brought by SP2, and are
fixed by hotfix 909095. In short, call Microsoft and ask "I want
the hotfix of KB909095"; MS will send you a free 2.5MB file that
fixes the problem.

Your case looks similar to one that hit me: Windows XP SP2
refused to hibernate when a Dial-up connection was running.
After 909095-hotfixed, Windows XP SP2 will still refuse, but
with a message, that is more informative than usual: it tells
clearly and in plain English, that the driver of the modem was
unable to handle the hibernation request, and that an updated
driver may fix the problem; since giving the exact name of the
modem and of the requesting process (Hibernation), it greatly
helps fix the issue.

I think this hotfix 909095 may also improve the way the IP stack
answers to an hibernation request. So in your case I would first
get and apply that hotfix; it may fix your particular problem -
or at least help fix it.

Details in the Related Message below.

Paris, Thu 17 Aug 2006 16:53:00 +0200


----- Parent Message (links are clickable) -----
From: "David D." <[email protected]>
Newsgroup: news://msnews.microsoft.com/microsoft.public.windowsxp.network_web
Message: news://msnews.microsoft.com/[email protected]
Sent: Thu 13 Jul 2006 14:07:49 -0400 (18:07:49 GMT)
Subject: IP conflict (DHCP assigned) when hibernating on home
network

I have been researching postings about IP conflicts using DHCP.
Although there are tons of such postings, most have to do with
mixing DHCP with static IPs, or with split-second timing
problems, or with clearing IP conflicts after they have
occurred.

I suspect that my IP conflicts are related to leases expiring
and IP addresses being reassigned while the original lessee is
hibernating.

This is a home network with a cable-modem and a router that
serves as my DHCP server. There are no static IP addresses in
the DHCP IP pool range. Computers in my house are typically
hibernated rather than shut down, so that work in progress can
be left open, and so that the computers power on faster.

I have had intermittent IP conflicts with my old, wired Linksys
router. I eliminated that problem by setting the IP lease
length to three years.

My new router is a wireless Netgear, with both wired ports and
wireless connections. This may complicate things a little for
two reasons: (1) the Netgear router does not have a setting to
allow one to change the IP lease length, and the lease length is
pretty short, and (2) the same computer might have one wireless
connection and one wired connection. I prefer to keep wireless
disabled for increased security and higher bandwidth, but it is
often convenient to use wireless.

However, the problem still occurred with the old, wired-only
router.

My network is a mix of Windows XP, Windows 2000, and Linux-based
appliances (a pocket print-server appliance and a TiVo).

Will an expired IP lease be discovered on waking from
hibernation? Could hibernation be the problem? Or is there
some other issue that I should be looking at?

- David

----- Related Message (links are clickable) -----
From: "Michel Merlin" <[email protected]>
Newsgroup: news://msnews.microsoft.com/microsoft.public.windowsxp.general
Message: news://msnews.microsoft.com/[email protected]
Sent: Wed 16 Aug 2006 19:42:50 +0200 (17:42:50 GMT)
Subject: SOLVED by hotfix KB909095 (Hibernation disappears in
XP if 1GB or more)

The reason: The problem is when you upgrade RAM to high size
(1Gb or 2Gb), XPSP2 fails to enlarge accordingly the
pagefile.sys file; attempts to hibernate fail, either before or
after, and cause Windows to temporarily remove Hibernate from
the Shut Down options - but without alterating your personal
Power Profiles. Restart restores Hibernation - thus your
original profiles.

The fix: the hotfix of KB909095, that will be added in XP-SP3,
and that meanwhile you will get for free by calling Microsoft in
your country (2.5MB). Details below.
........................
http://support.microsoft.com/kb/909095
........................