Regarding smaller prefix for hijack protection

Suresh Ramasubramanian ops.lists at gmail.com
Thu Aug 30 07:00:27 CDT 2012


You might find your /24 routes filtered out at a lot of places that do
have sensible route filtering

But then yes, it'd protect you against the idiots who dont know bgp
from a hole in the ground anyway and let whatever hijacking happen

But I'd suggest do whatever such announcement if and only if you see a
hijack, as a mitigation measure.

On Thu, Aug 30, 2012 at 5:24 PM, Anurag Bhatia <me at anuragbhatia.com> wrote:
> Hello everyone!
>
>
>
> I tried looking on net but couldn't found direct answer, so thought to ask
> here for some advise.
>
> Is using /24 a must to protect (a bit) against route hijacking? We all
> remember case of YouTube 2008 and hijacking in Pakistan. At that time
> YouTube was using /22 and thus /24 (more specific) announcement took almost
> all of Google's traffic even when AS path was long. So Google's direct also
> likely sent packets to Pakistan. Later Google too used /24 (and I guess /25
> too to effect some region of internet). Similar case I remember for issue
> reported between Altus and hijacking by someone connected to Cleaveland
> exchange when ISP was using /23 and spammer used /24.
>
>
> So can we conclude that one should always use /24 to make sure that they
> loose as little as possible traffic during prefix hijacking?
>
>
> Also, if one uses /22 and /24 - will both prefixes will show in Global
> routing table? I know /24 will be prefered but will ISP see /22 as well or
> it will pop up only when /24 is filtered?
>
>
> For one of IP's of Google.com, it seems it is coming from /16 and /24
>
>
> http://bgp.he.net/ip/74.125.224.137
>
>
> How can one print similar result from a route server like say Oregon route
> views or any ISP's server? I always /24 when looking for that IP. (in
> simple words - how bgp.he.net does this magic of popping both prefixes? I
> failed to do get same result from HE's route server)
>
>
>
>
> Thanks!
>
> --
>
> Anurag Bhatia
> anuragbhatia.com
>
> Linkedin <http://in.linkedin.com/in/anuragbhatia21> |
> Twitter<https://twitter.com/anurag_bhatia>|
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-- 
Suresh Ramasubramanian (ops.lists at gmail.com)



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