On Apr 8, 2007, at 9:03 PM, Paul Vixie wrote:
dotis@mail-abuse.org (Douglas Otis) writes:
Good advise. For various reasons, a majority of IP addresses within a CIDR of any size being abusive is likely to cause the CIDR to be blocked. While a majority could be considered as being half right, the existence of the "bad neighborhood" demonstrates a lack of oversight for the entire CIDR, which is also fairly predictive of future abuse.
that sounds like a continuum, but my experience requires more dimensions than you're describing. for example, this weekend two / 24's were hijacked and used for spam spew.
Agreed. This was expressed recently as well. http://www.merit.edu/mail.archives/nanog/msg05351.html CIDRs should also conform with ASN boundaries and reputation tracks with announcements. Unfortunately an effort to create a black-hole operator's BCP failed to consider these issues. Many building their own reputation histories will also likely ignore this concern. This means John's advice remains valid, whether fair or not. Adopting transient tracking methods cope with this problem. -Doug