Page 765 - (ISC)² CISSP Certified Information Systems Security Professional Official Study Guide

UDP is often employed by real-time or streaming communications for

audio and/or video. The IP header protocol field value for UDP is 17
(0x11).

As mentioned earlier, the UDP header is relatively simple in
comparison with the TCP header. A UDP header is 8 bytes (64 bits)
long. This header is divided into four sections, or fields (each 16 bits
long):

Source port

Destination port

Message length

Checksum

Network Layer Protocols and IP Networking Basics

Another important protocol in the TCP/IP protocol suite operates at
the Network layer of the OSI model, namely, Internet Protocol (IP). IP
provides route addressing for data packets. It is this route addressing
that is the foundation of global internet communications because it
provides a means of identity and prescribes transmission paths.
Similar to UDP, IP is connectionless and is an unreliable datagram

service. IP does not offer guarantees that packets will be delivered or
that packets will be delivered in the correct order, and it does not
guarantee that packets will be delivered only once. Thus, you must
employ TCP on IP to gain reliable and controlled communication
sessions.

IPv4 vs. IPv6

IPv4 is the version of Internet Protocol that is most widely used
around the world. However, a version known as IPv6 is being
adopted both for private and public network use. IPv4 uses a 32-bit
addressing scheme, while IPv6 uses 128 bits for addressing. IPv6
offers many new features that are not available in IPv4. Some of
IPv6’s new features are scoped addresses, autoconfiguration, and

Quality of Service (QoS) priority values. Scoped addresses give