Switches and routers Flashcards
What is a multi-homed machine in networking?
A device with multiple network interfaces, such as a router, used to connect various networks.
What is the role of Layer 1 (Physical) devices like repeaters and hubs?
Repeater: Amplifies and corrects signal variations to extend network distances.
Hub: Duplicates signals to multiple ports, operating in a single collision domain.
How does a Layer 2 switch differ from a hub?
A switch forwards frames to specific ports using MAC addresses, creating individual collision domains for each port, reducing collisions.
A hub broadcasts signals to all ports, sharing a single collision domain.
What are the key hardware components of a router?
Input Buffers: Store incoming packets.
Routing Processor: Maintains routing tables and exchanges data.
Switching Fabric: Routes packets to the correct output buffers.
Output Buffers: Temporarily store packets before transmission.
What is the purpose of a router’s switching fabric?
To route packets efficiently from input to output buffers. Types include:
In-Memory Switching: Processes packets in memory.
Bus-Based Switching: Uses a shared bus for packet transfer.
Crossbar Switching: Provides redundant paths for packet forwarding.
What is Multi-Protocol Label Switching (MPLS)?
A method combining IP routing with virtual circuit benefits by assigning labels to packets for efficient forwarding, bypassing traditional IP lookup.
What are the key fields in an MPLS label header?
Label (20 bits): Guides packet routing.
Class of Service (3 bits): Defines quality of service.
Stack (1 bit): Indicates stacked labels.
Hop Limit (8 bits): Prevents infinite routing loops.
How does MPLS integrate with ATM networks?
LSRs (Label Switching Routers) use AAL to segment and forward MPLS-labeled packets.
ATM switches handle labeled packets as cells within the network.
What are techniques to optimize router performance?
Use ASICs (Application-Specific Integrated Circuits) for faster routing.
Employ efficient switching fabrics like bus-based or crossbar designs.
Parallelize routing functions to handle high traffic volumes.
What is the primary function of a router in networking?
Routers determine the best path for packets using IP addresses and connect different network types efficiently, managing multiple paths.
