Introduction to IP Flashcards
What two protocols are in IP?
TCP and UDP
What do we say is encapsulated within IP?
TCP and UDP
What is a common use for TCP and UDP?
moving data from one part of the network to another`
Where might TCP and UDP operate?
at the transport layer of the OSI model (sometimes OSI Layer 4)
What do TCP and UDP provide that IP does not?
multiplexing;
allows many diff apps to simultaneously communicate to a separate server
What does TCP stand for?
What is another name for it:?
transmission control protocol
connected oriented protocol
Describe how TCP works?
requires a formal connection setup and close (3-way handhake: SYN > SYN ACK > ACK RECEIVED)
handshake allows user to know data was verified as received, so delivery is considered “reliable”
can reorder messages that were received out of order
can retransmit data if no SYN ACK received
has a flow control mechanism to allow user to manage how much data is being sent
What does UDP stand for?
another name?
user datagram protocol
connectedless protocol
Why is UDP considered unreliable?
there is no formal connection made so there is also no acknowledgement of data being received
(thus no reordering of data or retransmissions)
What protocol does not have flow control?
UDP
What protocol is faster and is associated with real-time communication?
Why is it faster?
UDP
a formal connection does not have to be made between devices before data can be sent
What is an example of a connectionless form of communicating?
What are two protocols that use this form?
UDP
dynamic host configuration protocol (DHCP)
trivial file transfer protocol (TFTP)
What is DHCP used for?
assigns IP addresses to our devices
What is TFTP used for?
used to transfer files using UDP
In UDP communication using DHCP, who is responsible for making sure info is received on the other side?
the app, DHCP
What is an example of a connection oriented communication?
What are two protocols that use this form?
TCP
hypertext transfer protocol secure (HTTPS)
secure shell (SSH)
What does SSH do for the user?
provides an encrypted form of terminal communication between our systems
Who take responsibility is a packet was not received in a connection oriented communication?
TCP takes responsibility and resends missing packet based on what SYN ACK was not received
To complete the traffic flow between devices, what info do we need?
we need the servers IP address, a protocol (such as TCP or UDP), server application port number for that protocol
we also need the client IP address, protocol being used, associated port number with protocol being used
What are non-ephemeral ports?
permanent port numbers that are well known on the server (for ex; want to communicate with a web server, we know that the web server commonly uses TCP port 80)
commonly ports 0-1023, but can be anything
What is port 80 commonly associated with?
HTTP
What is port 443 commonly associated with?
HTTPS
What is a ephemeral port number?
temporary port number used by client when communicating with server
commonly assigned port 1,024 - 65,535
What are port numbers basically used for?
communication (not security)
Are TCP and UDP port numbers the same?
no
you can have a service running on TCP port 80 and another service running on UDP port 80 (not done in normal operation to avoid confusion)
When communicating between client and server, whose port number is random?
the client source port number
