[bind10-dev] question about configure option "zero-no-soa-ttl" in bind9

[zhanglikun]

Hi Mark,

I noticed there is one configure option " zero-no-soa-ttl " in bind9.  The comments for it in bind9's code is: "If the query was for a SOA record force the ttl to zero so that it is possible for clients to find the containing zone of an arbitrary name with a stub resolver and not have it cached."

My question is: what it will change if the negative response for soa query is cached?

My guess it will benefit to the query for the frequent deleted/added zones. Some zones may be added or deleted frequently, if the negative response for soa query is cached, the resolver only can get the newest zone information until the negative reponse expires. Am I right?

Thanks
Likun