Re: Newbie Needs Help: someone is announcing less-specific IPv6 (BGP) route on top of me

[nanog--- via NANOG <nanog () lists nanog org>]

2400::/12 is larger than any prefix allocated to a network. In fact it's a prefix allocated to ARIN, which 
sub-allocates prefixes to various North American networks.

A route to 2400::/12 is effectively a route to North America - well, part of it, because ARIN has more than one prefix.

Network operators can announce whatever they want to their customers. It's not uncommon for some customers to get 
summarized routes. Some ISP far away from America could be telling its customers "yes, I know how to get to North 
America".

This radar tool seems to be showing what ISPs tell it, without filtering such ISP-specific routes. You can see other 
"invalid" routes such as /128 routes in the same tool. Such routes won't propagate across the whole internet, by 
convention, but there's no rule that a single ISP can't use them.



On 30 August 2025 08:58:21 CEST, Pirawat WATANAPONGSE via NANOG <nanog () lists nanog org> wrote:
> Dear Gurus,
>
>
> Radar tool by Qrator [Reference: https://radar.qrator.net ] claims that
> Zenlayer Inc. [AS4229] is “umbrella-ing” me by announcing ‘2400::/12’ on
> top of my more-specific address block.
> The tool classifies it as a type of hijacking.
> [Disclaimer: apologies to Zenlayer if you didn’t do it; but that’s the
> information I received]
> My neighboring organization also has a more-specific block that falls under
> The Umbrella too.
>
> However, other tools (https://stat.ripe.net , https://irrexplorer.nlnog.net
> , https://bgp.he.net , etc.) seem unable to see that particular
> announcement.
>
> Questions:
> 1. Is Qrator claim true? (because I have already tried but cannot verify)
> 2. If so, should I be concerned?
> Even though I already ROA-ed *and* IRR-ed my own block, but if “the other
> end” doesn’t validate, it won’t do any good, correct?
> (Oh, yeah, the other end also has to somehow “not see” my longer-prefix.
> But that can happen as well, no?)
> 3. In that case, what more do I must do?
>
> I would extremely appreciate someone helping me out on this matter.
>
>
> Best Regards,
>
> Pirawat.
> _______________________________________________
> NANOG mailing list 
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