What happens when the DNS names exceed the maximum UDP packet size?

1545 pts.
Tags:
DNS
Network diagnostics and measurements
Packet Design
UDP
A DNS uses UDP packet to resolve IP addresses. What happens when the DNS names to be looked up exceeds 576 bytes (the maximum UDP packet size)? Can it be sent in two packets?

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So I looked up the specifications and it seems it will work just will take a little longer. IPV6 was built with this in mind though. So it will not delay DNS resolution in the future – now it might take a few extra seconds!

The Domain name system defaults to using UDP for queries and replies
with a DNS payload limit of 512 bytes. Larger replies cause an
initial truncation indication leading to a subsequent handling via
TCP with substantially higher overhead. A upward compatible
extension to DNS requests is specified which frequently permits
larger UDP responses reducing the need for use of TCP.

Read the full spec here circa 1997.

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