The Network Layer Flashcards
A system which defines how the global IP address space is split up
ADDRESS CLASS SYSTEM
A protocol used to discover the hardware address of node with a certain IP address
ADDRESS RESOLUTION PROTOCOL (ARP)
A list of IP addresses and the MAC addresses associated with them
ARP TABLE
A number assigned to an individual autonomous system
ASN (AUTONOMOUS SYSTEM NUMBER)
To set the boundaries of something
DEMARCATE
Where one network or system ends and another begins
DEMARCATION POINT
The column in a routing table that contains a row for each network that the router knows about
DESTINATION NETWORK
A technology that assigns an IP address automatically to a new device. It is an application layer protocol that automates the configuration process of hosts on a network
DHCP
A format of using dots to separate numbers in a string, such as in an IP address
DOTTED DECIMAL NOTATION
An IP address assigned automatically to a new device through a technology known as Dynamic Host Configuration Protocol
DYNAMIC IP ADDRESS
Protocols that are used for the exchange of information between independent autonomous systems
EXTERIOR GATEWAY
It is used to indicate if a datagram is allowed to be fragmented, or to indicate that the datagram has already been fragmented
FLAG FIELD
The process of taking a single IP datagram and splitting it up into several smaller datagrams
FRAGMENTATION
It contains values used by the receiving end to take all the parts of a fragmented packet and put them back together in the correct order
FRAGMENTATION OFFSET FIELD
A checksum of the contents of the entire IP datagram header
HEADER CHECKSUM FIELD
A four bit field that declares how long the entire header is. It is almost always 20 bytes in length when dealing with IPv4
HEADER LENGTH FIELD
A non-profit organization that helps manage things like IP address allocation
IANA (INTERNET ASSIGNED NUMBERS AUTHORITY)
A 16-bit number that’s used to group messages together
IDENTIFICATION FIELD
For a router, the port where a router connects to a network. A router gives and receives data through its interfaces. These are also used as part of the routing table
INTERFACE
Protocols here are used by routers to share information within a single autonomous system
INTERIOR GATEWAY
A highly structured series of fields that are strictly defined
IP DATAGRAM
An optional field and is used to set special characteristics for datagrams primarily used for testing purposes
IP OPTIONS FIELD
A mitigation tool that lets organizations use one public IP address and many private IP addresses within the network
NETWORK ADDRESS TRANSLATION (NAT)
The IP address of the next router that should receive data intended for the destination networking in question, or this could just state the network is directly connected and that there aren’t any additional hops needed. Defined as part of the routing table
NEXT HOP
They are ranges of IPs set aside for use by anyone that cannot be routed to
NON-ROUTABLE ADDRESS SPACE
A series of zeros used to ensure the header is the correct total size
PADDING FIELD
A protocol field is an 8-bit field that contains data about what transport layer protocol is being used
PROTOCOL FIELD
Special protocols the routers use to speak to each other in order to share what information they might have
ROUTING PROTOCOLS
An 8-bit field that can be used to specifiy details about quality of service or QoS technologies
SERVICE TYPE FIELD
An IP address that must be manually configured on a node
STATIC IP ADDRESS
32-bit numbers that are normally written as four octets of decimal numbers, used to create subnetworks
SUBNET MASK
The process of taking a large network and splitting it up into many individual smaller subnetworks, or subnets
SUBNETTING
An 8-bit field that indicates how many router hops in a datagram can traverse before it’s thrown away
TIME-TO-LIVE FIELD (TTL)
The total number of devices data passes through to get from it’s source to its destination. Routers try to choose the shortest path, so fewest hops possible. The routing table is used to keep track of this.
TOTAL HOPS
A 16-bit field that indicates the total length of the IP datagram it’s attached to
TOTAL LENGTH FIELD
