Ethernet Flashcards
3 primary functions provided by layer 2 data encapsulation
Data link layer addressing.
Detection of errors through CRC calculations.
Delimiting groups of bits into frames.
How dose QoS help support a network
Providing mechanisms to manage congested network traffic
LLC
It places information in the frame allowing multiple layer3 protocols to use the same network interface and media.
What are 2 services provided by the OSI network layer
Routing packets toward the destination.
Encapsulating PDUs from the transport layer.
Why dose layer 3 perform anding on destination IP and subnet?
To ID net address
3 characteristics of multicast address
A single packet can be sent to a group of hosts.
Multicast transmissions can be used by routers to exchange routing information.
Routers will not forward multicast addresses in the range of 224.0.0.0 to 244.0.0.255.
Private IPs
- 0.0.0/8
- 16.0.0/12
- 168.0.0/16
Public addresses
- 0
- 16-172.31
- 168
TCP and UDP
Port numbering
Use of checksum
Why are port numbers in TCP header of a segment
To enable a receiving host to forward the data to the appropriate application.
What information is added to the TCP transport layer header to ensure communication and connectivity with a remote network device?
Destination and source port numbers
What TCP mechanism used in congestion avoidance
Sliding window
What are the two ways that TCP uses the sequence numbers in a segment
To identify missing segments at the destination.
To reassemble the segments at the remote location.
Presentation layer
Compression
Encryption
UDP
Provides basic connectionless transport layer functions.
UDP relies on application layer protocols for error detection.
UDP is a low overhead protocol that dose not provide sequencing or flow control.
DHCP
Returned to pool when the lease expires
Show interfaces
Layer1 and 2 details of switch port
Where are Cisco debug output messages sent by default?
Console line
User EXEC mode
>
Priv EXEC
en
Global config
Conf T
Fast forward
Has the lowest latency
What 2 functions are primary functions of a routers
Packet forwarding.
Path selection.
SLAAC
Dynamic global IPv6 addressing to end devices without using a server that keeps a record of available IPv6 addresses.
::1
Tests internal config of IPv6 host
Segmentation
Process of dividing data stream into smaller pieces
Highest level
DNS
POP
Latency issue
In crease in host to host ping response times
Fire wall
State full packet filtering
Converged network
Reduce cost of deploying and maintaining the communication infrastructure
