Apologies for not responding sooner. This came to light with me on a forum where someone posted that they thought it strange that their MTA received an IP that is assigned to the DoD DNIC. Where I work I have the opposite issue. They have a lot of public IPv4 space and only use it internally never be advertised to the internet. Something I have never agreed With doing. Robert -----Original Message----- From: Richard Porter [mailto:richard@pedantictheory.com] Sent: Sunday, December 17, 2017 8:25 PM To: Robert Webb <rwebb@ropeguru.com> Cc: nanog@nanog.org Subject: Re: Companies using public IP space owned by others for internal routing Robert, I’ve heard of two cases recently, large companies (non carrier/ISP). One company looking to solve challenge with IPv6 and 6to4 and DNS. Also curious how wide-spread this is? Maybe just the kick in the butt for catching the elusive IPv6 unicorn? ~Richard
On Dec 17, 2017, at 3:30 PM, Robert Webb <rwebb@ropeguru.com> wrote:
Will anyone comment on the practice of large enterprises using non RFC1918 IP space that other entities are assigned by ARIN for internal routing?
Just curious as to how wide spread this might be. I just heard of this happening with a large ISP and never really thought about it until now.
Robert