reply to RARPSL
said by RARPSL:The new list of root server IPs is automatically fetched when it does an NS lookup for "." from one of the IPs in the hints file. The hints file specifies the list of initial IPs to query, which is usually the root name servers, but any resolving server upstream from you in the DNS hierarchy could technically be used for the initial query. For Bind and most other popular name server daemons, the only time this name server change will be an issue is when the daemon is first started if it picks the L-server IP from its hint file you will have to wait for that request to time out before it will try another to get the NS list. Once the daemon is established there is absolutely no impact even if you never update the named.ca hints file.
BTW: If you run your own DNS Server, update your ROOT-SERVERS list since one of them has changed its IPN and will in a few months go away (it has two IPNs right now and the old one will be withdrawn eventually).