Ethernet Switching Flashcards
What layer does Ethernet switching operate on?
Layer 2 of the OSI model.
What is the purpose of VLANs?
To subdivide broadcast domains into smaller, manageable segments.
What protocol prevents switching loops in Ethernet networks?
Spanning Tree Protocol (STP).
How does Network Access Control (NAC) enhance security?
It ensures controlled access as devices connect to the network.
What does Maximum Transmission Unit (MTU) define?
The default and maximum frame sizes for Ethernet transmission.
How does CSMA/CD help with Ethernet collisions?
It detects and resolves network collisions by managing retransmissions.
What is the difference between a switch and a hub?
A switch creates separate collision domains per port; a hub shares one collision domain.
What is the function of a router?
It routes traffic between networks and breaks up broadcast domains.
What is a Layer 3 switch?
A switch that performs routing functions and connects network segments.
What is 802.1Q VLAN tagging used for?
To identify VLANs on trunk links and separate traffic.
What is the Native VLAN?
The VLAN that handles untagged traffic, often set to VLAN 1 by default.
What is a Voice VLAN used for?
A dedicated VLAN for VoIP traffic that prioritizes call quality.
What is link aggregation?
Combining multiple links to increase bandwidth and redundancy.
What is the difference between full-duplex and half-duplex?
Full-duplex allows simultaneous sending/receiving, while half-duplex does not.
What is a broadcast domain?
A group of devices that receive broadcast traffic from each other.
What is a collision domain?
A network segment where data packet collisions can occur.
What do Access Control Lists (ACLs) do?
They filter network traffic for security within VLANs.
What is the role of the Spanning Tree Protocol (STP)?
To prevent loops and ensure redundant links are managed.
What is a VLAN?
A Virtual Local Area Network that segments a physical network into logical networks.
How do VLANs improve network security?
They isolate network traffic, preventing unauthorized access between VLANs.
What is the purpose of VLAN tagging (802.1Q)?
It marks network frames to identify VLAN membership on trunk links.
What is the default VLAN ID on most switches?
VLAN 1.
What is a VLAN trunk?
A single physical link that carries traffic for multiple VLANs.
What is a Native VLAN?
The VLAN that handles untagged traffic on a trunk port.
What is the benefit of using VLANs?
Improved security, reduced broadcast traffic, and better network management.
What does the Spanning Tree Protocol (STP) prevent?
Switching loops in Ethernet networks.
How does STP choose a root bridge?
By selecting the switch with the lowest Bridge ID (BID).
What are the main port roles in STP?
Root Port, Designated Port, and Blocking Port.
What is a root port in STP?
A port with the best path to the root bridge on a non-root switch.
What is Rapid Spanning Tree Protocol (RSTP)?
An improved STP version (802.1w) with faster convergence.
What is a broadcast storm?
A network loop that causes continuous packet forwarding, overwhelming the network.
What is Network Access Control (NAC)?
A security method that inspects and authenticates devices before granting network access.
What is MAC Filtering?
A method of allowing or blocking devices based on their MAC addresses.
What is 802.1X authentication?
A framework that requires authentication before granting network access.
What are the two types of NAC agents?
Persistent agents (permanent) and non-persistent agents (temporary).
What is a quarantine network?
A restricted network segment for non-compliant devices until they meet security requirements.
What is role-based NAC?
A method that grants network access based on user roles (e.g., Admins vs. Guests).
What is MTU (Maximum Transmission Unit)?
The largest frame size that can be transmitted over a network without fragmentation.
What is the default Ethernet MTU size?
1500 bytes.
Why is MTU important?
It impacts network performance by controlling data transmission efficiency.
What happens if MTU is set too high?
Packets may be fragmented, leading to inefficiency and increased latency.
What is Jumbo Frame MTU size?
9000 bytes, used in high-speed networks like data centers.
What is the ideal MTU size for VPN traffic?
1400-1450 bytes to accommodate encapsulation overhead.
How can you test MTU settings?
Using a ping test with the â-fâ flag to prevent fragmentation.
