PXEcapability

PXEcapability is a term used to describe the collective set of network boot capabilities supported by a PXE-enabled client or environment. It encompasses the protocols, boot files, and features that may be leveraged during the initial boot sequence over the network. While not an official standard, PXEcapability is used in documentation, management tools, and deployment scripts to summarize compatibility and to drive automated provisioning decisions.

Common components include support for DHCP-based discovery and boot, the choice between TFTP and HTTP/HTTPS as the transport for boot images, and the ability to fetch a boot file by name. It may also indicate whether the client is BIOS/legacy or UEFI, whether iPXE features are available (such as chainloading or custom menus), and whether secure boot or signature verification is supported.

Negotiation in actual deployments occurs during the PXE boot exchange, where the client and server exchange parameters that reflect capabilities. Tools may generate or interpret a PXEcapability profile to select appropriate boot images, reduce failure, and streamline automated deployments. Implementations vary by vendor and by environment; some use vendor-specific extensions or iPXE's more extensive feature set to articulate capabilities.

Security considerations include ensuring that capability information does not reveal sensitive network topology, securing boot images via signatures, and using encrypted transport where available. Administrators may restrict capabilities to prevent unauthorized boot sources.

See also: Preboot Execution Environment, iPXE, DHCP, TFTP, UEFI network boot.