Configuring the nofirewall option by the sysrescue-initialize script must be done before the ip6?tables service.
Configuring the firewall should be finished before beginning to initialize the network.
But the rest of sysrescue-initialize should still be done in parallel to networking
being set up for a fast boot sequence. Also some services in sysrescue-initialize require
networking being online, for example load_srm with a remote url.
The proper way to accommodate all these needs is to split sysrescue:
sysrescue-initialize-prenet: must be finished before the network-pre.target
sysrescue-initialize-whilenet: started after sysrescue-initialize-prenet, can run in parallel
to networking being set up.
