On 7/29/08 2:56 PM, "Mike O'Connor" <mike@xxxxxxxxxx> wrote:
at this point my plea is for converging definitions rather than
diverging. i'm feeling the need to get a stake in the ground and move ON.
i'm meh on the "compromised vs plurally-purposed" debate and can go
either way.
routing was discussed in previous email, and i find the "discard it"
arguments more compelling.
"intent" has been discussed in previous email AND two phone
conversations, and i find the "discard it" arguments more compelling.
"change in TTL" correction duly noted -- Dave, you want to comment on
that? is it low TTL, or *changing* TTL, or both?
m
At 01:44 PM 7/29/2008, Joe St Sauver wrote:
>#A Fast Flux network is, for purposes of this working group:
>#
># * operated on one or more compromised {"plurally-purposed?"} hosts
>
>"Plurally-purposed" strikes me as a phrase that will distract rather than
>inform readers of this definition. Everyone knows what a compromised machine
>is, but I've never ever heard someone refer to a "plurally-purposed" host.
>
># * operated for the purpose of hosting unauthorized, malicious or
>#criminal content
># {delete? - "illegal vs political" issue}
>
>Do not delete. This is a key attribute.
>
># * operated using software that was installed {on hosts} without
>#notice or consent to the
># system operator/owner
># * "volatile" in the sense that the network changes its topology
>#for the specific
># purpose of sustaining the lifetime of the network and the
>#attack(s) the network supports, using:
>
>As I've previously mentioned, the topology of the network actually doesn't
>change, only its instantiation on specific hosts.
>
># o (rapid) modification of TTLs for name servers and
>#malicious content hosts
>
>Also as previously noted, the TTLs themselves do NOT change; if you see
>a fastflux host with a TTL of 120 seconds, it will NOT later have a TTL
>of 7200 seconds.
>
># {threshold? 1700 changes a month is avg TTL of 1525}
>
>That assumes you catch all changes, and that a given dotted quad is never
>used for more than one TTL's worth of time. In reality, a particular dotted
>quad hosting a fastflux host may have a TTL of 120, but may be used for
>an hour or more if there's no need to change it.
>
># o monitoring to determine/conclude that a host has
been identified
># and shut down {by its owner? how do we identify?}
>
>Also as previously mentioned, if the fastflux host is being used in classic
>reverse proxy mode, the backend host has intrinsic monitoring capabilities
>since it can see where the traffic it receives is coming from
>
># o time- or other metric-based topology change {how do we
>identify?}
>
>I don't know what this means.
>
># * {Limit the problem to "within the scope of ICANN to address"
># o Operation of the DNS system
># o Registration services
># o System-operators can't be reached/contacted
># o Does NOT include; routing, end-point security, etc.}
>
>Again reiterating points that have been previously made, but apparently
>not selected for inclusion by our gentle scribe, :-), routing (at least to
>the extent that ASN's are being manipulated by miscreants) is or should
>be in scope, and if you don't deal with end-point security, you've
>basically determined that fastflux is out of scope, because fastflux is
>all about a phenomena that is hosted on, and relies upon, insecure
>end points.
>
>To emphasize the routing component, one of the easiest ways to quickly
>identify fastflux hosts is by watching for a diversity of ASNs associated
>with the IPs mapping to a domain name. If you exclude that approach, you
>significantly weaken your ability to readily and mechanically identify
>fastflux hosting.
>
>Ignoring the role of routing also discounts the way many abuse complaints
>get routed these days ("if you route it, you're responsible for what
>comes out of it").
>
>Regards,
>
>Joe
>
>Disclaimer: all opinions strictly my own
>
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