It should just work out of the box if you have a router. Are you wanting to assign the IP manually?
I haven't memorized the steps and locations, but you should be able to copy an example from /etc/netctl/examples to /etc/netctl/MYETHERNET and change the IPs listed manually. For static, I think the example file is /etc/netctl/examples/ethernet-static
Did my ethernet page turn up? Details there which should also fit the June image, although only last tested on May image but I believe the changes mentioned to /bin, /sbin, etc. should not affect netctl, just location of apps and commands that are not in the /etc directory.
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