Companies using public IP space owned by others for internal routing

Tyler Conrad tyler at
Sun Dec 17 22:57:08 CST 2017

I worked alongside a company that used addresses assigned to the Syrian
govt for their "guest" network. They were a pretty large org, presumably
this was done to reduce risk - firewall rules, accidentally leaking guest
prefixes to their internal nets, or just straight-up simplicity. They were
in a pretty heavily regulated industry with restrictions on what companies
they could do business with, so there probably wasn't a huge risk of

On Sunday, December 17, 2017, joel jaeggli <joelja at> wrote:

> On 12/17/17 14:30, 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.
> every time I seen a traceroute with 11/8 22/8 26/8 in it I am duly
> impressed.
> > Robert
> >

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