All, Open resolvers pose a security threat. I wanted to let everyone know about a search tool that can help you find the ones within your organization. Treat it like a big "BETA" stamp is across it, but please try it out and see if you can close down any hosts within your network. This threat is larger than the SMURF amplification attacks in the past and can result in some quite large attacks. I've seen this spilling out into other mailing lists (e.g.: juniper-nap and others). Please send feedback about links that should be included or documentation and spelling errors to me. openresolverproject.org Some basic stats: 27 million resolvers existed as of this dataset collection only 2.1 million of them were "closed". We have a lot to do to close the hosts, please do what you can to help. Thanks, - Jared