[unisog] Microsoft Windows 'DHCP RELEASE while SELECTING Bug' (re-send)

Elliot Metsger emetsger at jhu.edu
Fri Mar 5 18:17:46 GMT 2004


Irwin,

I've had issues with 2k and XP clients before... I dealt with this about
a year or more ago so I'm not sure if this is still an issue.  

I don't recall if what you described was the exact issue or not; we may
not have probed as deeply as you did.  When we researched our DHCP
problems, we determined that MS clients weren't sending a DHCPRELEASE on
graceful shutdown and if we forced them to send a DHCPRELEASE on
graceful shutdown our problem was solved.

We solved this by setting a DHCP vendor option for Microsoft clients
using ISC's DHCP server as follows:

(inside of our main dhcpd.conf)

# Microsoft vendor specific client options
option space MSFT;
option MSFT.release-on-shutdown code 2 = unsigned integer 32;

class "msft-w2k-xp-clients" {
        ## For XP and 2k clients
        ## Make them release lease on proper shutdown
        match if option vendor-class-identifier = "MSFT 5.0";
        vendor-option-space MSFT;
        option MSFT.release-on-shutdown 1;
}

You'd need to test this and see if it works for you.  If MS clients
"forget" their DHCP settings when they perform a DHCPRELEASE on graceful
shutdown, then they may never enter the INIT-REBOOT state.

Let us know if it works! 

Elliot

>>> Irwin Tillman <irwin at princeton.edu> 03/05/04 9:14 AM >>>
(This is a re-send; first attempt appears to have not gotten through.)

At Princeton we've been seeing DHCP problems due to a bug introduced in
Windows. Since I suspect many other schools with many mobile clients are
experiencing the same bug, I thought I'd post the details for you.

We call this the "Microsoft Windows DHCP RELEASE while SELECTING Bug." 

Briefly, a Windows 2000 client configured to obtain its IP address via
DHCP will
occassionally transmit a DHCPRELEASE message while it is in the DHCP
SELECTING
state. This is not correct DHCP behavior. Depending on the
implementation of the
DHCP server, it may cause the client to fail to receive a DHCP lease.

< snipped >



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