Systemd developer Tom Gundersen posted this week on Google+ about DHCP performance and working on reasonably-fast network configuration for systemd's networkd. Work by Tom and others in recent weeks of profiling their DHCP client library have dropped the time needed to obtain a DHCP lease from 500ms to less than 50ms, and then this week a DHCP lease can be acquired by networkd in as little as 750 microseconds.
There's still network performance improvements being worked on by systemd developers, as noted in the Google+ posting.
Systemd has been working on DHCP client and server support within libsystemd-network. Frequent Phoronix news contributor Markg85 pointed out to one of the Google+ comments that a sd-dhcp-server component isa soon coming to accompany sd-dhcp-client within systemd.
Most of this work seems to be making on-demand Linux containers a reality, Gundersen posted, "my main focus at the moment is containers. We can boot a whole operating system in a container in ~100ms (now including getting a network connection). That means that you can start your containers on demand without significantly affecting response time." Of course, it will benefit desktop users too, "Also, even on a laptop you do want a fast DHCP client so when your laptop comes out of sleep it will have a connection immediately (at least this used to be an annoyance for me, but I'm sure YMMV). We want to be faster than it takes to switch on your screen."