If you want to continue booting to pxelinux, no changes need to be made for 4.0, however, we recommend you update to the ipxe BIOS setting and change Option 67 to undionly.kpxe. Since ipxe boots over tcp, it can be 3x faster than pxelinux, which boots over udp.
*Note: 4.1sp1 or higher is required to use the boot manager password feature.
In version 4.0, the K2000 supports both BIOS and UEFI PXE booting. However, in order to do this, a DHCP server must be able to distinguish and accept the different architectures of BIOS and UEFI and be able to serve a boot file based on that architecutre. The K2000 built in DHCP server can do do this automatically.
Other DHCP servers either have problems with doing this or require special setup instructions.
Windows Server 2008 and lower will require a user to set option 67 to the boot file name required at the time of PXE booting. So, when using this version of Windows Server, if it is required to boot BIOS machines, then option 67 should be set to undionly.kpxe in the subnet of the machines being booted. However, if UEFI machines need to PXE boot, then option 67 should be set to ipxe.efi in the appropriate subnet.
For Windows Server 2012R2 and higher, please download the DHCP Configuration Guide attached to this article in order to appropriately configure this server.
At this time, we don't have specific settings for the different DHCP servers that are being used. As more customers move to 4.0, we will do our best to help with configuration, but we are unable to support the features of these servers. Some of them will require switching the boot file name at the time you require to boot a specific architecture. Other servers, are able to take the different architectures and deliver the appropriate boot file.
*PFSense DHCP server can deliver the appropriate boot file based on architecture, directions are on the pfSense dhcpd configuration for UEFI and BIOS PXE Boot.
Centos Linux 5.5 has been confirmed to be working with the newest settings, you can view them on the Linux DHCP Configuration via dhcpd knowledgebase article.
We are certain many Cisco and Linux servers can do this as well, we just don't have them to test. Here is how the K2000 dhcpd.conf file handles the boot file.
*where 192.168.0.8 equals the IP Address of the K2000 Server.