IT-341 Lecture 5 - NETWORK LAYER & transport layer- follows ch 6 and ch7
POST stands for
Power On Self Test that tests all the hardware components
The ARP table, routing table, arp cache and packet buffering is all stored in __________-
RAM
running IOS is booted up in
RAM
firmware is stored in ____
ROM
In which alternative to DHCPv6 does a router dynamically provide IPv6 configuration information to hosts?
SLAAC
ROM stores the ________ instructions
startup
The transport layer is responsible for establishing a ____________ connection between 2 _________ and delivering data between them
temporary, applications
class A ipv4 addresses go from....
0-126
a loop back address example is....
127.0.0.1
class b IP addresses go from
128-191
link local addresses are assigned automatically and are located in the block....
169.254.0.0/16.
class c ip addresses go from
192-223
Which number or set of numbers represents a socket?
192.168.1.1:80
The acronym ______________ is used to define the process that allows multiple devices to share a single routable IP address.
NAT
class d addresses go from
224 - 239
startup config is stored in
NVRAM
Which portion of the network layer address does a router use to forward packets?
Network portion
____________ is randomly chosen during the TCP session setup.
An initial sequence number (ISN)
Applications requiring TCP include:
Databases, Web browsers, Email clients.
Used to identify an application or service running in the server.
Destination Port
TCP features (4 of them)
Establishing a Session Reliable Delivery Same-Order Delivery Flow Control
During the boot process, where will the router bootstrap program look for the IOS image by default?
Flash
Some applications that use TCP
Http, FTP, SMTP, Telnet
Applications using UDP include:
Live audio streaming live video streaming Voice over IP (VoIP)
A router may have to fragment a packet when forwarding it from one medium to another medium that has a smaller
MTU
___ is designed to confirm that each segment reached its destination.
TCP
____ allows for the retransmission of missed segments.
TCP
____ is a better choice if .... Application in which all data must be fully received before any is considered useful.
TCP
_______ is considered reliable
TCP
__________is a better choice for: Applications whose segments must arrive in a very specific sequence to be processed successfully.
TCP
Which transport layer feature is used to guarantee session establishment?
TCP 3-way handshake
______________ use sequence numbers to uniquely identify and acknowledge each segment, keep track of segment order, and indicate how to reassemble and reorder received segments.
TCP segments
______ termination allows for parties to gracefully end a _______when no data is to be transferred (FIN flag).
TCP session
How does the network layer use the MTU value?
The MTU is passed to the network layer by the data link layer MTU stands for maximum transmission unit and allows you to determine the largest data size permitted on your connectio
Which action is performed by a client when establishing communication with a server via the use of UDP at the transport layer?
The client randomly selects a source port number.
Within a production network, what is the purpose of configuring a switch with a default gateway address?
The default gateway address is used to forward packets originating from the switch to remote networks.
Network congestion has resulted in the source learning of the loss of TCP segments that were sent to the destination. What is one way that the TCP protocol addresses this?
The source decreases the amount of data that it transmits before it receives an acknowledgement from the destination.
Adding overhead to ensure reliability for some applications could reduce the usefulness of the application and can even be detrimental. That is why __________ is good
UDP
____ is not considered reliable
UDP
_______ provides the basic functions for delivering data segments between the appropriate applications, with very little overhead and data checking.
UDP
________ is a better choice for applications that can tolerate some data loss during transmission, but delays in transmission are unacceptable.
UDP
What is an advantage of UDP over TCP?
UDP communication requires less overhead.
TCP flow control function relies on a 16-bit TCP header field called the________
Window size.
IPv4 has __________ of end to end connectivity
a lack of
Which type of IPv6 address is not routable and used only for communication on a single subnet?
a link-local address
RST flag
abruptly terminate a session also called a reset flag
TCP handles flow control by ________ the rate of data flow between source and destination for a given session.
adjusting
IP is _______ which means....
best effort, not all packets will get received
Which three fields are used in a UDP segment header? (Choose three.)
checksum, length, source port
the receiver doesn't know when a message is ________ in IP
coming
transport layer offers ______ oriented data stream support
connection
IP is a _________ protocol
connectionless
routers require a ____ and a _____
cpu and an OS
Which key combination allows a user to abort setup mode?
ctrl-C
the network layer is responsible for ________--
deencapsulation
an IPv4 packet has a DS field which stands for ________ and contains the _______
differentiated service, packet priority
establishing a session
ensures that the application is ready to receive the data
flow control
ensures that the receiver is able to process the data received
same order delivery
ensures that the segments are reassembled into the proper order
IOS image is stored in ___________
flash
When transporting data from real-time applications, such as streaming audio and video, which field in the IPv6 header can be used to inform the routers and switches to maintain the same path for the packets in the same conversation?
flow label
class e addresses
go from 240 - 254
IP is media______
independent
host forwarding decisions three destinations
itself, local host, remote host
Three types of applications that are best suited for UDP
live video and multimedia applications, voip and live streaming video simple request and reply applications, DNS and DHCP applications that handle reliability them selves snmp TFTP
default gateway has a ________ IP address in the same address range as other hosts on the network
local
reliable delivery
means lost segments are resent so that the data s received complete
The network layer is primarily concerned with....2things
providing end devices with a unique network identifier and directing data packets to destination hosts on other networks
What are three responsibilities of the transport layer? (Choose three.)
meeting the reliability requirements of applications, if any Correct! multiplexing multiple communication streams from many users or applications on the same network Correct Answer identifying the applications and services on the client and server that should handle transmitted data
If there are two or more possible routes to the same destination, the ___________ is used to determine which route is used in the routing table.
metric
FF02::1 is a all node....
multicast, all IPv6 enabled devices on the local link or network
By default_______________command will attempt to resolve IP addresses to domain names and port numbers to well-known applications. It is best for monitoring connections to a host.
netstat
_________ is an important network utility that can be used to verify the active connections in a host.
netstat
IPV4 and IPv6 are at the ___________ layer
network
three basic tings that enable reliability with TCP
numbering and tracking data segments transmitted from a specific host to a specific application, acknowledging received data, and retransmitting any unacknowledged data after a certain period of time.
memory in a router consist of 4 things
nvram, flash, rom, ram
one hop is equal to ...
one layer 3 device so if three routers between pcs, three hops
The data is delivered to the application layer________ it has been completely received and reassembled.
only when
router bootup process
perform POST -> Load bootstrap -> Locate and load operating system -> Configuration
POST
power on self test tests all the hardware and is stored in ROM
What are two functions that are provided by the network layer?
providing end devices with a unique network identifier, directing data packets to destination hosts on other networks
Undelivered TCP segments trigger ____________ . TCP segment __________ can make the congestion even worse.
re-transmission.
to cope with congestion, The source can ________ the number of bytes it sends before receiving an acknowledgment upon congestion detection.
reduce
transport layer can provide ______
reliability
transport layer provides services such as ______
reliability, flow control, multiplexing, connection-oriented data stream support
FF02::1:FFAE:F85F is a ....
solicited node multicast
The ________________ number is dynamically chosen by the sending device to identify a conversation between two devices.
source port
What is the purpose of using a source port number in a TCP communication?
to keep track of multiple conversations between devices
What is the purpose of the TCP sliding window?
to request that a source decrease the rate at which it transmits data
transport layer must keep_______________individual conversations
track of
What OSI layer is responsible for establishing a temporary communication session between two applications and ensuring that transmitted data can be reassembled in proper sequence?
transport
Which network migration technique encapsulates IPv6 packets inside IPv4 packets to carry them over IPv4 network infrastructures?
tunneling
The___________ is the number of bytes that the destination device of a TCP session can accept and process at one time.
window size
