An Infoblox DHCP appliance is being used to manage the distribution of DHCP addresses to client systems. However, when the Altiris PXE boot process is introduced to the DHCP environment, the client systems never receive the PXE Boot menu and cannot complete the PXE boot process.

The problem is DHCP option 66. This is the option that gives the IP address of the TFTP server.

The problem is that a client machine PXE booting doesn’t actually look at this option. Instead, clients are actually looking at the value: "Next Server IP address". If this entry is empty, or not defined the client machine PXE booting will assume that the DHCP server is also acting as the TFTP server (which is not the case in this environment). It can be seen by network captures that the PXE process gets to the point where the client makes a TFTP read request to the Infoblox server (which it can’t respond to, since it is not acting as a TFTP server.

Microsoft DHCP doesn’t have this problem, because when DHCP option 66 is specified, it then takes that option's data, and then sets the value of "Next Server IP address" with that data. The problem is that not all DHCP server automatically put the IP address of DHCP option 66 and put it into the "Next Server IP address". Some other DHCP servers do this, and some others do not.

Configure the Infoblox appliance option "next-server" to contain the same IP address as the "server-name" option.

From the Infoblox manual:

Grid Level

To configure support for BOOTP boot requests on a grid:

1. From the DHCP and IPAM Perspective, select DHCP Members -> id_grid -> Edit -> ID Grid DHCP Properties.
2. In the ID Grid DHCP Properties editor, click BOOTP.
3. Enter the following:
— Boot Server Name: Enter the name of the server on which the boot file is stored. Clients can request for
either the boot server name or IP address. Complete this field if the hosts in your network send requests for
the boot server name. If the TFTP server is the Infoblox device that is also serving DHCP, enter the name of
the Infoblox device.
— Next Server IP: Enter the IP address of the boot file server on which the boot file is stored. Complete this
field if the hosts in your network send requests for the IP address of the boot server. If the TFTP server is the
Infoblox device that is also serving DHCP, enter the IP address of the Infoblox device.
Note the you can complete both the Boot Server Name and Next Server IP fields, if some hosts on your
network require the boot server name and others require the boot server IP address.
— Boot File Name: The name of the file the client must download.
4. Click the Save and Restart Services icons.

Note: In at least one case of issues PXE booting with Infoblox DHCP, DHCP Snooping was required to be set to TRUST on the network ports for the PXE Sever. However, this may not be required for all PXE environments using Infoblox DHCP.

Applies To

DS 6.8 through 6.9 SP5

INFOBLOX DHCP Appliance with 4.2r3-7-38857 firmware