Well, this is my second time typing this post - the first time I clicked submit, the forum logged me out and I lost the lot! Frustrating! Oh well.
Our business recently acquired another, which comes with four users and a fully kitted-out win2k8 server (mail, file etc.). We're moving this other business in-house, and wish to place them on a separate subnet, so that their server and network can continue running as before.
The problem is that because of logistical and practical limitations with our building, we are forced to use EoP (ethernet over power) in place of cable drops. So our router is therefore configured with all the ports switched/bridged, and there's no possibility of using a dedicated port to connect the second organisation.
What I'd like to do, then, is place this second organisation behind a mikrotik router which is doing NAT in 'both directions' - so that any host can talk to any other host, and we can share resources. The simple network diagram should illustrate what I mean. Is this possible using hairpin nat or 1:1 nat or should I be looking at something else? I'm open to using a VLAN or something if someone would be kind enough to point me in the right direction. I've tried playing around with 1:1 NAT but didn't get anywhere so thought I would ask for help.
To repeat for clarity - there's no way that I can run a cable from our router to theirs. We can only use EoP, which just works as a L2 switch.
I presently have this second network just running behind a cheap home router which is working fine, except that we can't reach hosts on their network and I'd like a mikrotik-level of control over the traffic.