A company has recently switched ISPs and is being assigned a new block of public addresses. The public web and FTP servers must be re-addressed to support this change. After changing IP addresses and

DHCP records are used for dynamic IP address assignment within a local network and are unrelated to public DNS records for web and FTP servers.

PTR records (pointer records) are used for reverse DNS lookups (IP to hostname) and do not directly affect a client's ability to resolve a hostname to an IP address for forward lookups.

Reducing the Time-to-Live (TTL) on DNS records *before* changing IP addresses allows client-side DNS caches to expire existing records more quickly. When the new IP addresses are updated in DNS, client resolvers will request the new information much sooner after their cached entries expire, leading to faster propagation of the changes and less disruption for users trying to access the services.

Configuring a caching-only DNS server would not inherently make the transition more transparent; it primarily serves to improve resolution speed for subsequent lookups by caching records, not to accelerate the propagation of new records.