Harshith Mulky <harshith.mu...@outlook.com> wrote: > > 1. How is Negative Caching Applied for other RCODES : FORMERR, SERVFAIL, > REFUSED and NOTIMPL? What is the minimum TTL Value for these responses?
Good question: this isn't well specified. BIND has servfail-ttl (1s by default) and lame-ttl (600s by default). The lame-ttl can take effect in as a result of REFUSED responses amongst other things. NOTIMPL should not normally occur. FORMERR can trigger EDNS downgrade. > 2. Are the clients free to re-query the same DNS server if no caching is > applied for the above RCODES? In general the same question will yield the same answer so a good implementation should avoid and preferably suppress repeat queries. Tony. -- f.anthony.n.finch <d...@dotat.at> http://dotat.at/ Biscay, Fitzroy: Variable 3 or 4, becoming northerly or northwesterly 5 at times, occasionally 6 later in southeast Fitzroy. Slight or moderate. Showers. Good. _______________________________________________ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users