Cisco ENCOR Lan Switches 4 — Questions and Answers
Question 1: Which type of switch memory stores the IOS image that persists across reboots?
- RAM
- NVRAM
- Flash (Correct answer)
- ROM
Correct answer: Flash
Flash memory on Cisco switches stores the IOS image files and retains them when the device is powered off.
Question 2: A trunk link is carrying VLANs 10, 20, and 30. An administrator runs 'switchport trunk allowed vlan remove 20'. What is the result?
- VLAN 20 traffic is tagged but dropped at the far end
- VLAN 20 is removed from the trunk's allowed list and no longer passes (Correct answer)
- All VLANs except 20 are removed from the trunk
- The trunk is reset to allow all VLANs
Correct answer: VLAN 20 is removed from the trunk's allowed list and no longer passes
The 'remove' keyword removes the specified VLAN from the allowed VLAN list on the trunk, stopping all VLAN 20 traffic across that link.
Question 3: What does the Cisco switch feature 'Storm Control' protect against?
- STP topology changes from rogue switches
- Excessive broadcast, multicast, or unicast traffic flooding (Correct answer)
- ARP spoofing attacks
- Unauthorized MAC address changes
Correct answer: Excessive broadcast, multicast, or unicast traffic flooding
Storm Control monitors traffic levels on a port and takes action (drop or shutdown) when broadcast, multicast, or unicast traffic exceeds a configured threshold.
Question 4: In a VSS (Virtual Switching System) deployment, what is the primary benefit over a traditional dual-supervisor chassis?
- Doubled forwarding table size only
- Two physical switches appear as a single logical switch, enabling active-active forwarding (Correct answer)
- Spanning Tree is required between the VSS peers
- VSS is supported on all Catalyst platforms
Correct answer: Two physical switches appear as a single logical switch, enabling active-active forwarding
VSS pairs two physical chassis into one logical switch, enabling active-active data forwarding across both chassis and eliminating the need for STP between the pair.
Question 5: Which switch feature prevents IP packets from being forwarded when the source IP address does not match the DHCP snooping binding table entry for a port?
- Dynamic ARP Inspection
- IP Source Guard (Correct answer)
- Port Security
- BPDU Guard
Correct answer: IP Source Guard
IP Source Guard uses the DHCP snooping binding table to verify the source IP of packets, dropping any that do not match the expected binding for that port.
Question 6: Which spanning tree variant does Cisco recommend for modern campus networks to provide per-VLAN topology with rapid convergence?
- 802.1D STP
- PVST+
- Rapid PVST+ (Correct answer)
- MST only
Correct answer: Rapid PVST+
Rapid PVST+ combines the per-VLAN flexibility of PVST+ with the fast convergence of 802.1w RSTP, making it Cisco's recommended default for campus switching.
Question 7: What happens to traffic on a VLAN that is active on a switch but not present in the VTP VLAN database received from the VTP server?
- The VLAN is pruned and traffic continues
- The VLAN is deleted from the switch and its traffic is dropped (Correct answer)
- Traffic is forwarded using the native VLAN
- The switch ignores VTP updates for that VLAN
Correct answer: The VLAN is deleted from the switch and its traffic is dropped
In VTP client or server mode, when a VTP update removes a VLAN, the VLAN is deleted from the local database and all ports assigned to it lose their VLAN association.
Cisco ENCOR Lan Switches 4
Which type of switch memory stores the IOS image that persists across reboots?