Companies using public IP space owned by others for internal routing

Sun Dec 17 22:48:49 UTC 2017

RFC1918 isn't big enough to cover all use cases. Think about a large
internet service providers. If you have ten million customers, 10.0.0.0/8
would be enough to number modems, but what happens when you need to number
video set top boxes and voice end points? I don't think anyone goes out and
says "Lets go use someone else's space, because I don't want to use this
perfectly good private space".

On Sun, Dec 17, 2017 at 3:42 PM, Richard <rgolodner at infratection.com> wrote:

>
>
> On 12/17/2017 04:30 PM, Robert Webb 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
>>
>>
>>     It is more common than you would think. Why use public IP's when you
> can have many rfc1918 options. Always amazes me after the initial confusion.
>     Richard
>