nanog mailing list archives

Re: Prefix hijacking, how to prevent and fix currently


From: Job Snijders <job () instituut net>
Date: Fri, 29 Aug 2014 12:25:59 +0200

On Fri, Aug 29, 2014 at 06:17:09AM -0400, Sandra Murphy wrote:
Loose mode A would look like this:

   In the case that 10.0.0.0/16 origin AS123 is not in your table, the
   loose mode would kick in and one could accept more specifics for
   10.0.0.0/16, but only when originated by AS123.

Loose mode B would look like this:

   In the case that 10.0.0.0/16 origin AS123 is not in your table, the
   loose mode would kick in and one could accept more specifics for
   10.0.0.0/16 originated by any ASN.

The major point is that when the valid route is missing, one might
choose to accept invalid routes. When the valid route returns, the
invalids are purged from your table.

Or in other words: Proposal is, that when additional 'loose' mode is
configured, invalid routes are accepted if and only if they are the only
route to destination. If there is any other route (less-specific) which
is not invalid, it will be used, instead of the invalid route.

In your examples, you presume there's a ROA for the less-specific.

Correct.

Here you say "not invalid", which would mean a route that is
"unknown", i.e. no ROA exists.

Sorry, with "not invalid" i meant "valid".

Your Loose Mode A relies on the existence of the ROA - you accept more
specifics but only when originated by the ASN in the ROA.

I'd like to accept more-specifics, only in the absense of the
less-specific ROA covered prefix.

So which do you mean?  The less specific has a ROA or the less
specific may not have a ROA?

The less specific has to have a ROA, for any loose mode to make sense.

Loose mode A & B came into existence 15 minutes ago, its good to discuss
what a loose mode could mean. ;-)

Kind regards,

Job


Current thread: