PVST+ CCNA Questions

-
1.What is one benefit of PVST+?

A. PVST+ supports Layer 3 load balancing without loops.
B. PVST+ reduces the CPU cycles for all the switches in the network.
C. PVST+ allows the root switch location to be optimized per VLAN.
D. PVST+ automatically selects the root bridge location, to provide optimized bandwidth usage.

Answer: C

Explanation:
Per VLAN Spanning Tree (PVST) maintains a spanning tree instance for each VLAN configured in the network. It means a switch can be the root bridge of a VLAN while another switch can be the root bridge of other VLANs in a common topology. For example, Switch 1 can be the root bridge for Voice data while Switch 2 can be the root bridge for Video data. If designed correctly, it can optimize the network traffic.
2. When PVST+ in work on VLAN1 of the switch, what will affect on selection of one of switches in the VLAN as root-bridge?
A. Lowest IP address
B. Highest MAC address
C. Lowest MAC address
D. Highest IP address
Answer: C
Explanation

The two values used to select the root bridge are Bridge Priority & MAC address (the lower is better) -> C is correct.

3. Which port state is introduced by Rapid-PVST?
A. learning
B. listening
C. discarding
D. forwarding
Answer: C
Explanation
PVST+ is based on IEEE802.1D Spanning Tree Protocol (STP). But PVST+ has only 3 port states (discarding, learning and forwarding) while STP has 5 port states (blocking, listening, learning, forwarding and disabled). So discarding is a new port state in PVST+.

Comments

Post a Comment

Popular posts from this blog

7 Popular Layer 2 Attacks

-
Image
A large number of common threats need to be considered when securing a network, but a frequently overlooked area is the security of the LAN. When people think about security, often they’re thinking specifically of the layers above Layer 2, but there’s no reason to limit a security plan to these upper layers.  A good security plan should account for  all  layers, from Layer 1 through Layer 7.   Here we are discussing about some of the most common Layer 2 attacks and how they operate. 1. Spanning Tree Protocol (STP) Attacks The Spanning Tree Protocol (STP) is used on LAN-switched networks. Its primary function is removing potential loops within the network. Without STP, Layer 2 LANs simply would stop functioning, because the loops created within the network would flood the switches with traffic. The optimized operation and configuration of STP ensures that the LAN remains stable and that traffic takes the most optimized path through the network.  If an att
Read more

CCNA Latest Dumps Part 3

-
Image
QUESTION 21 Refer to the exhibit. The two connected ports on the switch are not turning orange or green. What would be the most effective steps to troubleshoot this physical layer problem? (Choose three.) A. Ensure that the Ethernet encapsulations match on the interconnected router and switch ports. B. Ensure that cables A and B are straight-through cables. C. Ensure cable A is plugged into a trunk port. D. Ensure the switch has power. E. Reboot all of the devices. F. Reseat all cables. Correct Answer: BDF QUESTION 22  A network administrator is troubleshooting the OSPF configuration of routers R1 and R2. The routers cannot establish an adjacency relationship on their common Ethernet link The graphic shows the output of the show ip ospf interface e0 command for routers R1 and R2. Based on the information in the graphic, what is the cause of this problem? A. The OSPF area is not configured properly. B. The priority on R1 sho
Read more

Nine Switch Commands Every Cisco Network Engineer Needs to Know

-
Image
1. hostname Syntax:   hostname   hostname One of the most basic network commands,  hostname  configures the hostname used for a device. This hostname identifies the device to other locally connected devices for protocols such as the Cisco Discovery Protocol (CDP), which helps in the identification of devices attached directly to the network. Although it is not case-sensitive, the hostname must follow certain rules: It must begin with a letter and end in a letter or digit, and interior characters must be letters, digits, or hyphens (-). 2. ip default-gateway Syntax:   ip default-gateway  gateway The  ip default-gateway  command configures the default gateway for a switch when IP routing is  not  enabled (with the  ip routing  global configuration command), which is typical when lower-level Layer 2 switches are being configured. The easiest way to determine whether IP routing has been enabled is to run the  show ip route  command. When IP routing has not bee
Read more