Any network interface card (NIC) supported by the Linux kernel are also be supported by the boot disks. All network drivers are compiled as modules so you need to load one first during the initial network setup. The list of supported network devices is:
Channel to Channel (CTC) or ESCON connection (real or emulated)
lcs: OSA-2 Token Ring/Ethernet or OSA-Express Fast Ethernet (non-QDIO)
Inter-User Communication Vehicle (IUCV) - available for VM guests only
qeth: OSA-Express in QDIO mode / HiperSockets - this requires a second initrd with the OCO modules from developerWorks. Please read Abschnitt 4.3, „Creating an IPL tape“ for information how to get or create such a second initrd.