The Network Layer Flashcards
On a local area network or LAN, nodes can communicate with each other through
their physical MAC addresses
8 Bits
Byte
a single octet
can represent all decimal numbers from 0 to 255
Under the IP protocol, a packet is usually referred to as
an IP datagram.
The two primary sections of an IP datagram are
the header and the payload.
What happens to the TTL field of an IP datagram every time it reaches a router?
router decrements the TTL field by one.
subnetting is the process of taking a
large network and splitting it up into many individual smaller subnetworks or subnets.
A gateway router specifically
serves as the entry and exit path to a certain network.
What does CIDR stand for?
Classless Inter-Domain Routing
CIDR notation uses a
forward slash and then lists the numbers of bits in the subnet mask.
How many octets does a subnet mask have?
4
Who is permitted to use non-routable address space
Anyone
ARP stands for
address resolution protocol
The entirety of a packet at one layer becoming the payload section at another layer
encapsulation
The process of taking a large network and splitting it up into many individual and smaller subnetworks is known as
subnetting
A subnet ID is calculated via a
subnet mask
A network device that knows how to forward data along to other networks is known as
router
TTL
time to live
interior gateway protocols are used by routers in order to share information within a single
autonomous system
RFC stands for
Request for Comments
Ranges of IP address that anyone can use for their internal networks are known as
non-routable address space
The transport layer is responsible for
multiplexing and demultiplexing traffic, establishing long running connections and ensuring data integrity through error checking and data verification.
Multiplexing in the transport layer means
that nodes on the network have the ability to direct traffic toward many different receiving services.
Demultiplexing is the same concept, just at the
receiving end, it’s taking traffic that’s all aimed at the same node and delivering it to the proper receiving service.
The transport layer handles
multiplexing and demultiplexing through ports.
16-bit number that’s used to direct traffic to specific services running on a networked computer.
A port
A server or service is
a program running on a computer waiting to be asked for data
A client is another program
that is requesting this data.
The destination port is the port
of the service the traffic is intended for,
A TCP segment is made up of a TCP
header and a data section.
sequence number. This is a 32-bit number that’s used
to keep track of where in a sequence of TCP segments this one is expected to be.
The sequence number in a TCP header is used
to keep track of which segment out of many this particular segment might be.
data offset field is a four-bit number that communicates
how long the TCP header for this segment is. This is so that the receiving network device understands where the actual data payload begins.
a 16-bit number known as the TCP window. A TCP window specifies the range
of sequence numbers that might be sent before an acknowledgement is required.
