Concise Guide to DNS and BIND, The

Of RRsets

An RRset is the set of RRs associated with a name. In any zone there is at least one name which has several records associated with it. This is an extract from the penguin.bv zone as shown in Chapter 2, "DNS in Practice":

@       3600    SOA     ns.penguin.bv.  hostmaster.penguin.bv. (
                2000042924      ; serial
                86400           ; refresh, 24h
                7200            ; retry, 2h
                3600000         ; expire, 1000h
                172800          ; minimum, 2 days
                )
                NS      ns
                NS      ns.herring.bv.
                MX      10 mail
                MX      20 mail.herring.bv.
...
@               A       192.168.55.3
@               A       192.168.55.10
...

Associated with the name penguin.bv are one SOA record, two NS records, two MX records, and two A records. This makes one RRset. In RFC 2181, which updates RFC 1035, it is specified that all records in an RRset must have the same TTL. This RFC is listed as ...