Why can my IBM T60 laptop not resolve IP addresses from DHCP or PXE?

Mohamed bilal October 29, 2010

I am using an IBM t60 laptop with Windows 7.

I have a server running Windows 2008 R2 and it’s a WDS Server. All the PCs (ca. 10 HP DC7100) are running Windows 7 and getting IP in PXE enivironment and DHCP as well.

The problem is, with this IBM laptop I cannot resolve the IP from either DHCP or PXE. If I fix the IP manually it’s working very fine. I have tested network card, cable, switch, all the possiblities maximum, but it’s still giving problems. Any ideas please?

  1. Anonymous
    October 30, 2010 at 11:18 am

    HiThe problem usually occurs when your DHCP pool is full (i.e. every address that can be allocated by the DHCP server has been used, or is reserved). If you restart the DHCP daemon (which should release all the IP addresses), does this still happen?You could set up a virtual machine on one of your servers and enable DHCP on the VM. Then you can test as much as you like with a sniffer running on the VM without having to make any potentially damaging network configuration changes to any of your servers (especially since the servers are rented and they most likely have vendor-specific management utilities installed and possibly some custom configuration by your hosting provider to optimize performance within that environment).Proxy DHCPhttp://adf.ly/91637/banner/http://en.wikipedia.org/wiki/Preboot_Execution_Environment#Proxy_DHCPConfiguring your DHCP infrastructure to support PXE servers is usually limited to adding option 60 depending on where the PXE server is locatedIn order to support PXE clients on a network, the DHCP server is usually configured in one of the following three modes: Option 60 not set, Option 43 not set Option 60 set to 'PXEClient', Option 43 not set Option 60 set to 'PXEClient', Option 43 set When neither option 60 nor option 43 is set, PXE clients will have no clue on where the PXE server is, and they will therefore wait until a PXE server contact them. In this mode, the PXE server must listen to DHCP discovery packets sent by PXE clients and answer at the same time as the DHCP server does. When option 60 is set to 'PXEClient', it means that the DHCP server knows where the PXE server is. If option 43 is not set, the PXE server is on the same computer as the DHCP server (same IP address). If option 43 is set, PXE clients must decode option 43 to know how to reach the PXE server. In most situations, option 43 does not need to be setup, because the PXE server will either listen to DHCP discovery packets (DHCPProxy), or be on the same computer as the DHCP server. However, if the PXE server is on a separate subnet (it cannot listen to DHCP discovery packets), or if there are several PXE servers on the same subnet, option 43 is the only viable solution in order to instruct PXE clients on what to do. Option 43 is a binary buffer, containing a list of sub-options. Sub-options are packed in the binary buffer, in no specific order. Most sub-options are optional. An exhaustive list of sub-options can be found in the PXE specifications


  2. Mike
    October 30, 2010 at 7:17 am

    Sounds like a tough one...

    ~ make sure DHCP range has enough hosts
    (at this point you could also add an DHCP Reserve for the MAC of the T60)

    ~ try booting the T60 in Safe Mode with Networking enabled (F8 etc.)

    ~ check the T60 bios settings
    (normally IBM Access button > Setup Utility; maybe put PXE first in boot order and see if it is working)

    As always, one step at a time :-)
    drop a note about your progress... curious myself what the problem is