Hiya, Thanks - fine answer to my not-quite-discuss.
Cheers, S. On 04/01/15 09:39, Adrian Farrel wrote: > Hi Stephen, > > I'd like the authors and shepherd to pitch in, but... > >> - I'd have thought that these TLVs would be sent more often than >> others, and that (if enormous amounts of money are in play) then >> use of OSPF authentication might be more likely needed (or some >> equivalent security mechanisms). I'd even speculate that if >> enormous amounts of money are in play, then confidentiality may >> become a requirement (since if I can observe say A bit settings >> then that might give me insight into traffic levels - sort of a >> lights burning at night in central bank implies interest-rate >> change attack). Can you say why none of that needs to be mentioned >> at all? Was any of that considered by the WG? (Can you send a >> relevant link to the archive?) > > I think you are raising two points: 1. Are the TLVs sent more often > than others and what are the implications? 2. What can be learned > from sniffing these TLVs? > > To the first point, I don't think they are sent more often than other > TE TLVs. Indeed metrics for loss and delay may be more stable than > others, and Section 5 addresses measurement intervals and projects > that on to announcement thresholds. > > So the risk is that changes in bandwidth availability will cause > rapid or frequent announcement of those metrics. However, just like > the original bandwidth metrics, implementations apply thresholds so > that small changes don't trigger re-announcement in order to avoid > stressing the network. Section 6 discusses this. > > Thus, I think we can discard 1. > > The second point is important: you can find out a lot about a network > by sniffing the IGP, and if your plan is to understand the state of > your competitor's network or to find the week spots to attack, then > this is a powerful tool. But in this matter I would argue that these > no TLVs are no more sensitive than other, pre-existing TLVs, although > (of course) the more TLVs, the more information is available to be > sniffed. > > So, the question is how do we protect IGP information as it is > advertised within a network. There are four elements: - IGP > information is retained within an administrative domain. - If a > router is compromised it has access to all of the information and > there is nothing we can do. - If a node attempts to join a network to > access the information it will be unknown and will not be able to > peer. - If a link is sniffed (which is a somewhat more sophisticated > attack) protection relies on encryption of the messages most probably > at layer 2, but potentially at IP (which is an option for OSPF) or > within the OSPF messages themselves. > > I think all of this is just "IGP security as normal", was discussed > by KARP, and is everyday business for network operators. > > [snip] > >> - The security considerations of RFC 3630, from 2003, is 11 lines >> long. Has nothing affected OSPF security in the last decade+ that >> would be worth noting here? > > That is a good point. There is plenty of newer security work. > > Adrian > _______________________________________________ OSPF mailing list OSPF@ietf.org https://www.ietf.org/mailman/listinfo/ospf
