One of your team members has asked you to analyze the following SOA record. What is the TTL? Rutgers.edu.SOA NS1.Rutgers.edu ipad.college.edu (200302028 3600 3600 604800 2400.

200302028 is the serial number, which functions as the zone's version identifier and is not the TTL.

3600 appears as both the refresh interval (how often secondaries poll for updates) and the retry interval (how long to wait after a failed refresh), neither of which is the TTL.

604800 is the expire value, defining how long a secondary nameserver will serve zone data if it cannot reach the primary - this is not the TTL.

The SOA record parenthetical fields follow a fixed order: serial, refresh, retry, expire, and minimum TTL. The fifth value (2400) is the minimum TTL, which defines how long resolvers cache negative responses (NXDOMAIN) for the zone. This field was repurposed for negative caching TTL per RFC 2308, making 2400 the correct answer for TTL in this record.

The value 60 does not appear anywhere in this SOA record.

The value 4800 does not appear anywhere in this SOA record.