The DNS resolver code (optionally to be compiled into Etherboot) allows for filenames to contain hostnames. Thus,
might in theory be a valid file to be downloaded (you will have to compile-in HTTP support as well).
DNS resolver code will only work if a nameserver has been configured inside your DHCP config. Most regular hostnames are expected to work: A (adress) and CNAME (alias) records are allowed for a certain depth. There is no support for IPv6 hostname resolution yet, but that will not do any harm as Etherboot does not yet support IPv6 anyway.
Hostnames may only be used in fully specified URIs of the form
:port part may be omitted.
protocols include “http”, “tftp”, “nfs”, and “x-tftp”.
SLAM might or might not work with DNS… .