[TechBro8615]

Way back when, I was working at a startup with little clue what I was doing. Long story short, I setup a VPN network to connect 600 devices through 8 wifi routers to a VPC. I used 11.0.0.0/8 because I didn't want to bother sorting through the conflicts with 10.x, 192.168.x, and 172.x which were all used at various places throughout the chain (e.g. the routers on 192, some upstream services on 10.x and 172.)

All I had to do to make it work, IIRC, was add an ip routing rule to prioritize our internal routing for traffic on 11.0.0.0/8 instead of sending it over the default interface.

This solution worked fine, but it broke in weird ways and I remember one time I did arp -a on one of the Amazon boxes and saw some DoD registered addresses, which was a little alarming, but I just chalked it up to my not understanding the details.

[twic]

I did the same with 51/8 back when that was owned by the UK Department of Work and Pensions but not publicly routable.