On 29 May 2012, at 18:33, Richard Barnes wrote: >>>>>> i can tell more than that. rover is a system that only works at all >>>>>> when everything everywhere is working well, and when changes always >>>>>> come in perfect time-order, >>>>> Exactly like DNSSEC. >>>> >>>> no. dnssec for a response only needs that response's delegation and >>>> signing path to work, not "everything everywhere". >>> >>> My impression was that ROVER does not need "everything, everywhere" to work >>> to fetch the routing information for a particular prefix -- it merely needs >>> sufficient routing information to follow the delegation and signing path >>> for the prefix it is looking up. However, I'll admit I haven't looked into >>> this in any particular depth so I'm probably wrong. >> >> RPKI needs the full data set to determine if a BGP prefix has the status >> 'valid', 'invalid' or 'unknown'. It can't work with partial data. For >> example, if you are the holder of 10.0.0.0/16 and you originate the full >> aggregate from AS123 and a more specific such as 10.0.1.0/24 from AS456, >> then you will need a ROA for both to make them both 'valid'. If you only >> authorize 10.0.0.0/16 with AS123, then the announcement from AS456 will be >> 'invalid'. If you only authorize 10.0.1.0/24 from AS456, the announcement >> from AS123 will remain 'unknown'. >> >> So in RPKI, partial data – so you failed to fetch one of the ROAs in the set >> – can make something 'invalid' or 'unknown' that should actually be 'valid'. >> http://tools.ietf.org/html/rfc6483#page-3 > > I wouldn't read that as saying that the RPKI requires you to have full > data in order to provide any benefit. Where sufficient certs and ROAs > exist to validate an announcement, you can mark it valid/invalid -- > just like ROVER, but with a harder failure case.
I don't mean that you need ROAs describing every route announcement in existence for it to be useful. What I mean is for an operator to determine if a route announcement is RPKI valid, invalid or unknown, they will need *all* ROAs that *have been created*. If they miss a ROA in the data set during the fetching process, a route can end up with the incorrect validity state. See my example. >> As far as I know, ROVER doesn't work like that. You can make a positive >> statement about a Prefix+AS combination, but that doesn't mark the >> origination from another AS 'unauthorized' or 'invalid', there merely isn't >> a statement for it. (Someone please confirm. I may be wrong.) > > Of course, there's a reason that an announcement that contradicts a > ROA is marked as invalid [RFC6483]. Such announcements are hijacks, > the attacks that the RPKI is designed to prevent. If ROVER doesn't > provide a hard fail here, then it would seem to not be providing much > security benefit. That does seem the case. I don't think ROVER provides a hard fail. Can someone confirm? > I agree with the person higher up the thread that ROVER seems like > just another distribution mechanism for what is essentially RPKI data. But does that distribution method easily allow you to get the full set of available data? -Alex
