These days, some cloud hosting environments still didn’t offer dhcp6 services (for example Hetzner Cloud) – therefore it’s impossible to use an automated ipv6 configuration with iPXE.
But a static configuration can still be used:
File: config.ipxe#
#!ipxe echo static ipv6 ipxe configuration # ip set net0/ip6:ipv6 fe80::10 set net0/len6:int8 64 set net0/gateway6:ipv6 fe80::1 # dns - hetzner https://wiki.hetzner.de/index.php/Hetzner_Standard_Name_Server set net0/dns6:ipv6 2a01:4f8:0:1::add:1010