DDoS Mitigation Survey

[Merike Kaeo <kaeo@merike.com>]

I am looking for added input to my initial isp security practices 
draft.  Specifically I'd like to make sure the 01 version will have 
clear information regarding what techniques are deployed for DDoS 
mitigation.   The following questions need some resolution.....

- Where does loose vs strict uRPF get used?
- Why would loose uRFP not be used?
- What (if any) is problem with using remotely triggered blackhole 
routing?
- Where does destination based vs source based triggered blackhole 
routing get used?
- Do triggers usually get deployed based on traffic filters to all 
routers or are they BGP community based?
- Where are prefix filters vs AS filters used?  Why?
- Any other DDoS mitigation techniques which are deployed today?

I had some info from initial survey and am sifting through NANOG 
archives since some of these issues have been discussed there.  
However, would appreciate any discussion or insights on this list from 
folks that are deploying these techniques and are able to comment 
publicly.

- merike