TCP/IP

Network defense and countermeasures chapter 2 key terms

anycast

An address created automatically when a unicast address is assigned to more than one interface. addresses are assigned from unicast address ranges and have the same scopes as unicast addresses

Broadcast

A communication sent to all hosts on a specific network.

Classless Interdomain Routing (CIDR)

An IP address notation method that uses a slash (/) followed by the number of masked bits for an address ex. 192.168.6.5/27 instead of an IP address of 192.168.6.5 and a subnet mask of 255.255.255.224.

Datagram

A discrete chunk of information; each one contains source and destination addresses, control settings, and data.

Domain Name System (DNS)

A Network service that provides a database for the resolution of fully qualified domain names to IP addresses, and of IP addresses to fully qualified domain names.

Footer

A section sometimes added to a TCP/IP packet to indicate the end of the packet.

fragmentation

The division of packets into smaller sizes to accommodate routers with frame size limitations.

header

The part of a packet that contains source and destination information and general information about the packet.

host identifier

The part of an IP address that is unique to a computer in its subnet.

Internet Control Message Protocol (ICMP)

A protocol that reports network communication errors to support IP communications. The ping command is a common troubleshooting utility based on this protocol.

Internet Protocol version 4 (IPv4)

The IP addressing system currently in widespread use on the Internet, in which addresses are created with 32 bits (4 bytes) of data.

multicast

A transmission used for one-to-many communication, in which a single host can send packets to a group of recipients.

Multicast Listener Discovery (MLD)

A core IPv6 protocol that enables IPv6 routers to discover multicast listeners on a directly connected link and to decide which multicast addresses are of interest to those nodes.

Neighbor Discovery

A core IPv6 protocol used to resolve addresses, locate neighboring routers, and redirect hosts to better routes to reach destination addresses. It uses ICMPv6 messages to manage node-to-node communications.

Network Address Translation

A process by which internal hosts are assigned private IP addresses and communicate with the Internet using the public address of the NAT device.

Network Identifier

The part of an IP address that a computer has in common with other computers in its subnet.

scopes

Unicast addresses used in IPv6 to identify the application suitable for the address; this include global unicast, site-local unicast, and link-local unicast.

stateful autoconfiguration

In IPv6, the method of dynamic host configuration that uses DHCPv6. The method is called “stateful” because the DHCPv6 client and server must keep their information updated to prevent addressing conflicts.

stateless autoconfiguration

A feature of IPv6 in which a computer can connect to a network by determining its own IP address based on the addressing of neighboring nodes.

subnet mask

A value that defines which part of a computer’s IP address is its network identifier and which part is the host identifier.

Transmission Control Protocol/Internet Protocol (TCP/IP)

A suite of protocols for transmitting information from point to point on a network.

Unicast

A transmission in which one packet is sent from a server to each client that requests a file or application.

User Datagram protocol

A core transport protocol of the TCP/IP suite. It is connectionless, meaning it does not ensure delivery or provide ordering, as TCP does. This protocol is much faster, and is useful for transmissions that require speed over reliability. It relies on upper-level protocols for error-checking and sequencing services.

Variable Length Subnet Masking (VLSM)

A means of allocating IP addressing according to the network’s needs that involves applying masks of varying sizes to the same network. This method creates subnets within subnets and multiple divisions of an IP network.