iPxe.kpxe or undionly.kpxe, which is to choose ?

[cpservicespb]

Which file ipxe.kpxe or undionly.kpxe is to choose to boot via network ?
And what is each other intended for ?

[NiKiZe]

You should use ipxe.pxe (not .kpxe) or undionly.kpxe

It mainly depends on if you want iPXE native drivers which in some cases are faster, and in many cases provides more features (such as vlan support) over undionly.
in some cases undionly does not work eighter, even if that is rare, read more at https://ipxe.org/appnote/buildtargets

[cpservicespb]

So, what is the fastest way for booting itself and booting images, is to use ipxe.pxe or undionly.kpxe ?

I built ipxe by myself.
And there is one nasty thing.
If I use ipxe.pxe, booting hans up after Features banner and Ctrl+B request, there is no even net configuration process shown.
If I use undionly.kpxe from the same compiled version, all is good.
And autoboot from shell do not work as well in case of ipxe.pxe.