ICND1 LAN Switching Technologies 3

Question 1

Which EtherChannel negotiation protocol is Cisco proprietary?

Accepted Answer

PAgP

Answer

Port Aggregation Protocol (PAgP) is Cisco proprietary, while LACP is the IEEE 802.3ad standard.

Question 2

What happens when a port configured as a PortFast port receives a BPDU?

Accepted Answer

BPDU Guard shuts the port if enabled

Answer

If BPDU Guard is enabled, receiving a BPDU on a PortFast port immediately puts the port in err-disabled state.

Question 3

How many bits make up a VLAN ID in an 802.1Q tag?

Accepted Answer

12

Answer

The VLAN ID field in an 802.1Q tag is 12 bits, supporting VLAN IDs 0–4095.

Question 4

Which type of switch attack exploits the limited size of the MAC address table to force flooding?

Accepted Answer

MAC flooding attack

Answer

A MAC flooding attack fills the CAM table so the switch floods all frames, allowing an attacker to capture traffic.

Question 5

What is the purpose of a native VLAN on an 802.1Q trunk?

Accepted Answer

It is used for untagged frames traversing the trunk

Answer

The native VLAN carries untagged Ethernet frames across an 802.1Q trunk link.

(ICND1) Interconnecting Cisco Networking Devices Part 1 Practice Test