Thanks all and sorry for being nitty:-) S
On 05/01/15 15:00, John E Drake wrote: > Acee, > > I will take care of Stephen's nits and add the references you mention > to the Security Considerations. > > Yours Irrespectively, > > John > >> -----Original Message----- From: OSPF >> [mailto:[email protected]] On Behalf Of Acee Lindem (acee) >> Sent: Monday, January 05, 2015 9:51 AM To: [email protected]; >> 'Stephen Farrell'; 'The IESG' Cc: [email protected]; >> [email protected]; draft-ietf-ospf-te-metric- >> [email protected] Subject: Re: [OSPF] Stephen Farrell's >> No Objection on draft-ietf-ospf-te- metric-extensions-09: (with >> COMMENT) >> >> Hi Stephen, Adrian, >> >> On 1/4/15, 4:39 AM, "Adrian Farrel" <[email protected]> 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. >> >> >> Agreed. This is covered in sections 5 and 6. >> >>> >>> 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. >> >> >> I agree. I can¹t see that delay/loss would be more sensitive than >> reachability information. I guess the premise is that one might >> want to target better for links for DDoS attacks? I do not recall >> this coming up in the discussions on either the OSPF or ISIS lists >> (there is an ISIS draft advertising the same TLVs). >> >> >>> >>> [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. >> >> This should include RFC 6863 for analysis, RFC 5709 for protection, >> and draft-ietf-ospf-security-extension-manual-keying-11 for >> protection. John? >> >> Thanks, Acee >> >> >>> >>> Adrian >>> >> >> _______________________________________________ OSPF mailing list >> [email protected] https://www.ietf.org/mailman/listinfo/ospf > _______________________________________________ OSPF mailing list [email protected] https://www.ietf.org/mailman/listinfo/ospf
