Companies using public IP space owned by others for internal routing

james machado hvgeekwtrvl at
Mon Dec 18 01:10:14 CST 2017

I had a vendor at $dayjob prior to my arrival who assigned all their
customers ip space based on the customer number.  when i got there all the
internal network was assigned space from an company in the middle east.
$dayjob didn't have the in-house knowledge to know what was going on and as
they never worried about the middle east it didn't affect their business.

On Sun, Dec 17, 2017 at 3:25 PM, Jens Link <lists at> wrote:

> Matt Hoppes <mattlists at> writes:
> > Had a previous employee or I discovered it on the network segment after
> > we had some weird routing issues and had to get that cleaned up. I don't
> > know why anyone would do that when there is tons of private IP space.
> Excuse 1: "We'll never connect to the internet!"
> Excuse 2: "It's only temporary!"
> Excuse 3: Typo (At some customers customer I found 192.!168 address which
>           where apparently a typo but in use for years so nobody wanted
>           to change it.) I also know one company who is using (has
>           used?) 2001:8db::/48. I suggested to get v6 PI an properly
>           implement IPv6 but never heard from them again.
> Excuse 4: "We used the addresses from out training material." - I heard
>           this story some time ago: A large German government agency
>           wanted to implement IP(v4) and the people attended a course
>           about this new TCP/IP stuff at $Vendor. The training material
>           was prepared by a student who was using his university's /16 as
>           an example.
> BTW: Is the Cisco WLC as default address for DHCP?
> Jens
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