Hello ENUMmers, I'm about to become responsible for a Tier-2 ENUM registry, part of the Irish ENUM Trial. I expect to use BIND as the name server platform for this purpose. I have supposed (perhaps naïvely) that the conventional delegation mechanism, using NS records in the parent zone, would be appropriate. This involves creating a new zone as each new telephone number is registered, and configuring the zone specifically on each of Tier-2 name servers. I'm not sure I really want to buy in to this level of per-number provisioning activity, and see apparently significant advantages in using the technique of RFC2317 (Classless IN-ADDR.ARPA delegation) to make life simpler. The advantages I see are the following. The Tier-1 zone file becomes smaller, with just one CNAME (or DNAME) record per delegation, rather than two or more NS records. At Tier 2, the named configuration file needs only per-server, rather than per-number- per-server provisioning activity, and propagation of newly-registered numbers is driven by NOTIFY rather than by reloading the updated configuration file on each server. This looks like the way to go, but perhaps I'm missing something ? Best regards, Niall O'Reilly UCD Computing Services