It happens occasionally that some remote name server goes ``bad''. You can tell your name server to refuse to listen to or ask questions of certain other name servers by listing them in a bogusns directive in your named.boot file. Its syntax is the same as forwarders, xfrnets, and sortlist -- you just give it a list of dotted-quad Internet addresses. Note that zones delegated to such servers will not be reachable from clients of your servers; thus you should use this directive sparingly or not at all.