The port that receives the best BPDU on a bridge is the root port .

This example shows how to increase the probability that the spanning tree instance on access port interface 2/0 is chosen as the root bridge by changing the port priority to 32:

switch(config-if)# spanning-tree port-priority 32

C. to obtain VLAN information from directly connected switches - You can get the Native VLAN.

D. to verify Layer 2 connectivity between two devices when Layer 3 fails - Can get information even without L3.

E. to obtain the IP address of a connected device in order to telnet to the device - You can get the Management Address of a Switch.

However, D and E are the best options.

VTP protocol has 3 modes Server,CLient & Transperent.There is only 1 server and all other switches in that environment are Clients.

Only server can create,modily and delete VLAN's so in VTP environment VLAN's are consistent across the network.

The changes made on the Server are automatically propogated to all the clients through the TRUNK links established between the switches.

=> CE is correct.

To communicate between two different VLANs we need to use a Layer 3 device like router or Layer 3 switch -> B is correct.

VLANs don’t affect the number of collision domains, they are the same -> C is NOT correct. Typically, VLANs increase the number of broadcast domains.

We must use a different network (or sub-network) for each VLAN. For example we can use 192.168.1.0/24 for VLAN 1, 192.168.2.0/24 for VLAN 2 -> D is correct.

A switch maintains a separate bridging table for each VLAN so that it can send frame to ports on the same VLAN only. For example, if a PC in VLAN 2 sends a frame then the switch look-ups its bridging table and only sends frame out of its ports which belong to VLAN 2 (it also sends this frame on trunk ports) -> E is correct.

Different VLANs can't communicate with each other, they can communicate with the help of Layer3 router.

Hence, it is needed to connect a router to a switch, then make the sub-interface on the router to connect to the switch, establishing Trunking links to achieve communications of devices which belong to different VLANs.

Lightweight APs (LAPs) is devices require no initial configuration. LAPs use the Lightweight Access Point Protocol (LWAPP) to communicate with a WLAN controller (WLC). Controller-based APs are useful in situations where many APs are required in the network. As more APs are added, each AP is automatically configured and managed by the WLC.

https://www.cisco.com/c/en/us/products/collateral/security/web-security-appliance/guide-c07-742373.html

“4.1 Web proxy

Caching should be enabled in the web proxy configuration in order to save bandwidth and boost performance. This is becoming less important as the percentage of HTTPS traffic increases because the WSA does not by default cache HTTPS transactions. If the proxy is deployed to serve only explicit clients, forward mode should be specified in order to reject any traffic that isn’t specifically destined for the proxy service. This reduces attack surface in the appliance and follows a good security principle: If you don’t need it, turn it off."

Whenever a switch receive a frame, it look in MAC address table for a matching entry. And if not found, switch will forward to (Flood) all the ports in the switch except the port that received.

More Hints:

Sometimes called BUM traffic - Broadcast, Unknown Unicast, Multicast.

These forms of traffic are "flooded" out all ports except the port the packet was received on.