This draft, "BLACKHOLE BGP Community for Blackholing", describes a new optional BGP community with the specific semantics of "please blackhole this traffic for me". The idea is to have a single common community instead of all the ad hoc communities that ISPs have created for this semantic. The beginning of the security considerations section is daunting in that it says, in essence, "BGP has no authentication, so injecting dangerous messages is trivial; thus this new dangerous community is not a problem". It then goes on to say "and this new community can be used as a DoS by your downstream peers because they can tell you lies, but you were already susceptible to those lies". And then "and this can be used for CPU exhaustion against you if you're not careful" without saying how to be careful. There are currently two active threads on ietf@ about security implications of this draft. There are questions about whether this draft lacks enough specificity to prevent CPU exhaustion attacks even from well-meaning peers, whether it should be standards track given that it is underspecified, whether it should suggest that IXPs should implement it, and other questions seem to be coming up. I think that this document *might* be OK as an Informational RFC if there is more discussion about how to prevent a CPU exhaustion attack for recipients and more MUSTs instead of SHOULDs for what other communities need to be applied to these messages. --Paul Hoffman