nanog mailing list archives

Re: [External] announcing IPs by scrubbing service to help with DDoS attacks and ROAs


From: Amir Herzberg <amir.lists () gmail com>
Date: Fri, 17 Nov 2023 20:34:01 -0500

Tom, thanks. I'm an academic researcher, no a network operator, sorry for
the confusion, I should have been clearer.

The practice you described indeed shouldn't requite ROA. I didn't even
consider it, probably since I've been working so much on prefix hijacks,
and this prefix would result in increased vulnerability to prefix hijacks.
But if there's only a DDoS attack on the prefix and it's not being hijacked
at the same time, then I think this practice may be fine - which would make
such `emergency ROA' unnecessary.
So that's very very useful feedback, thanks a lot!! Amir
-- 
Amir Herzberg

Comcast professor of Security Innovations, Computer Science and
Engineering, University of Connecticut
Homepage: https://sites.google.com/site/amirherzberg/home
`Applied Introduction to Cryptography' textbook and lectures:
https://sites.google.com/site/amirherzberg/cybersecurity




On Fri, Nov 17, 2023 at 12:09 AM Tom Krenn <Tom.Krenn () hennepin us> wrote:

It has been a few years, but I recall advertising my routes to the
scrubbing center via a tunnel and just prepending to my other peers when in
mitigation. This was pre-RPKI days, but my ASN was still originating the
route. So, I would assume no change in ROA would be needed in that
scenario. Are you allowing them to originate your routes or are they just
another hop in your as-path?



Tom Krenn

Network Architect

Enterprise Architecture - Information Technology

[image: Hennepin County logo]





*From:* NANOG <nanog-bounces+tom.krenn=hennepin.us () nanog org> *On Behalf
Of *Amir Herzberg
*Sent:* Thursday, November 16, 2023 19:58
*To:* NANOG <nanog () nanog org>
*Subject:* [External] announcing IPs by scrubbing service to help with
DDoS attacks and ROAs



*CAUTION:* This email was sent from outside of Hennepin County. Unless
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Hi, do people use scrubbing services, when under DDoS attack, by having
the scrubbing service announce the attacked IP prefix(es)?



If so, and you have a ROA for these prefixes, do you authorize the
scrubbing AS (by issuing ROA or otherwise), and if so, do you do it in
advance or only when you need the scrubbing service to announce your
prefix?



To clarify: we have a possible method to allow such `emergency ROAs' but
I'm not convinced if we have a solution to a real problem - or if we just
found a cute crypto solution and will end up writing it for a non-real
problem. I prefer not to waste our time on presenting cute solutions to
non-real problems :)



So thanks for your help! Use your judgement if to respond on list or off
list.



Many thanks, Amir

--

Amir Herzberg



Comcast professor of Security Innovations, Computer Science and
Engineering, University of Connecticut

Homepage: https://sites.google.com/site/amirherzberg/home

`Applied Introduction to Cryptography' textbook and lectures:
https://sites.google.com/site/amirherzberg/cybersecurity






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