ACSP Virtual Router Redundancy (VRRP) 2 — Questions and Answers
Question 1: In VRRP, what happens when a backup router receives an advertisement with a priority lower than its own?
- It immediately becomes the master (Correct answer)
- It ignores the advertisement
- It sends a priority update to the current master
- It resets the master-down timer
Correct answer: It immediately becomes the master
A backup router will preempt and become master if it receives an advertisement with a priority lower than its own, provided preemption is enabled.
Question 2: Which VRRP timer controls how long a backup router waits before declaring the master as down?
- Advertisement interval
- Master-down interval (Correct answer)
- Preemption delay timer
- Hold-down timer
Correct answer: Master-down interval
The master-down interval (skew time + 3 × advertisement interval) determines when a backup declares the master as down.
Question 3: What is the VRRP skew time used for?
- Synchronizing clocks between routers
- Staggering master-down timers among backup routers based on priority (Correct answer)
- Setting advertisement intervals
- Delaying preemption after a topology change
Correct answer: Staggering master-down timers among backup routers based on priority
Skew time staggers master-down timers among backup routers so that higher-priority backups take over before lower-priority ones.
Question 4: On an ArubaOS-Switch, which command verifies the current VRRP master for VRID 10 on VLAN 20?
- show vrrp vlan 20 vrid 10 (Correct answer)
- show vrrp statistics vrid 10
- show ip vrrp vlan 20
- show redundancy vrrp 10
Correct answer: show vrrp vlan 20 vrid 10
The 'show vrrp vlan <vlan-id> vrid <vrid>' command displays the current VRRP role, priority, and master IP for the specified VRID.
Question 5: What is the default VRRP advertisement interval on Aruba switches?
- 100 ms
- 500 ms
- 1 second (Correct answer)
- 3 seconds
Correct answer: 1 second
The default VRRP advertisement interval is 1 second, during which the master sends multicast hellos to keep backups informed.
Question 6: A VRRP group is configured with two routers: Router A at priority 120 and Router B at priority 90. If Router A fails and later recovers, what occurs when preemption is enabled?
- Router B remains master permanently
- Router A reclaims the master role after recovery (Correct answer)
- Both routers enter an election and the one with the higher IP wins
- The VRRP group resets to default priority
Correct answer: Router A reclaims the master role after recovery
With preemption enabled, a recovering router with higher priority will send advertisements and reclaim the master role from the current lower-priority master.
Question 7: Which statement is TRUE about VRRP and ARP in a standard deployment?
- Each VRRP router responds to ARP for the virtual IP independently
- Only the VRRP master responds to ARP requests for the virtual IP (Correct answer)
- All backup routers respond to ARP with the virtual MAC address
- ARP is disabled when VRRP is active
Correct answer: Only the VRRP master responds to ARP requests for the virtual IP
Only the VRRP master responds to ARP requests for the virtual IP address, ensuring hosts point to a single active gateway.
ACSP Virtual Router Redundancy (VRRP) 2
In VRRP, what happens when a backup router receives an advertisement with a priority lower than its own?