Network Fundamentals Flashcards
Frames are a PDU on what layer?
Layer 2
What is the PDU for layer 3?
Packet
What is layer 7 in the OSI model?
Application
What is layer 6 in the OSI model?
Presentation
What is layer 5 on the OSI model?
Session
What layer does encryption and decryption occur in the OSI model?
Layer 6, presentation
What is layer 4 on the OSI model?
Transport
Name protocols on layer 4
TCP and UDP on the transport layer
Describe TCP
Transmission Control Protocol
Connection oriented (Delivery confirmation)
Sequencing and segmentation
Reliable delivery
Describe UDP
User Datagram Protocol
Connectionless (No delivery confirmation)
No sequencing or segmentation
Best effort delivery
Name layer 3 of the OSI model.
Network
What does the network layer do?
Routing
Logical Addressing
IP, ICMP NAT, OSPF
What is layer 2 of the OSI model?
Data Link
What happens at layer 2?
Flow control Acknowledgements Error detection Logical Link Control Media Access Control
What is layer 1 of the OSI model?
Physical
What happens at layer 1?
Electrical and mechanical characteristics
per cable, fiber optic cable
IEEE 1394 and BASE standards
What is IGP?
Interior Gateway Protocols are routing protocols used within an autonomous system (AS), such as company routers.
What is EGP?
Exterior Gateway Protocols are used to map routes between
autonomous systems and are mainly utilized by ISPs.
What is RIP?
Routing Information Protocol –
- The RIP hop count metric will choose the path with the least amount of hops, where hops refer to routers.
- Max number of hops is 15
- RIP operates in layer 7 (OSI) and uses port 520 (UDP)
- Default AD value is 120
What is OSPF?
Open Shortest Path First – The OSPF metric is based on cumulative
bandwidth from source to destination. OSPF will
choose the path with the highest bandwidth.
What is Distance Vector?
Distance vector is a routing algorithm that calculates the best path for a packet
based on the factors of distance and vector.
What is distance with respect to dynamic routing?
Distance: The distance between the router and the destination network, based on
the metric of number of hops (routers)
What is vector with respect to dynamic routing?
Vector: The outgoing interface and the direction to the path that leads to the
destination network
