ACSP Virtual Router Redundancy (VRRP) 3 — Questions and Answers
Question 1: What is the virtual MAC address format used by VRRPv2?
- 00-00-5E-00-01-{VRID} (Correct answer)
- 00-00-0C-07-AC-{VRID}
- 00-1A-1E-00-01-{VRID}
- FF-FF-5E-00-01-{VRID}
Correct answer: 00-00-5E-00-01-{VRID}
VRRPv2 uses the virtual MAC format 00-00-5E-00-01-{VRID} where VRID is the Virtual Router Identifier in hex.
Question 2: In VRRPv3, which significant improvement was made over VRRPv2?
- Support for IPv6 and sub-second advertisement intervals (Correct answer)
- MD5 authentication for advertisements
- Support for up to 512 virtual routers per interface
- Automatic load balancing across all group members
Correct answer: Support for IPv6 and sub-second advertisement intervals
VRRPv3 (RFC 5798) added native IPv6 support and allows sub-second advertisement intervals for faster failover.
Question 3: What VRRP feature can be used to track an upstream interface so the master lowers its priority if the uplink fails?
- VRRP authentication
- VRRP object tracking (Correct answer)
- VRRP preemption delay
- VRRP advertisement suppression
Correct answer: VRRP object tracking
VRRP object tracking monitors a specified interface or route and decrements the VRRP priority if the tracked object goes down, triggering failover.
Question 4: When configuring VRRP on Aruba switches with object tracking, what happens to the VRRP master priority when the tracked interface goes down?
- Priority increases by the configured decrement value
- Priority decreases by the configured decrement value (Correct answer)
- Priority resets to 0 and master role is lost immediately
- Priority is set to 255 to force re-election
Correct answer: Priority decreases by the configured decrement value
When the tracked object fails, the master's priority is reduced by the configured decrement, potentially causing a backup with higher resulting priority to preempt.
Question 5: In a two-router VRRP setup, both routers report as master simultaneously. What is the most likely cause?
- Both routers have the same VRID configured
- The advertisement multicast traffic between the routers is blocked (Correct answer)
- VRRP preemption is disabled on both routers
- The virtual IP matches both routers' physical IP addresses
Correct answer: The advertisement multicast traffic between the routers is blocked
A split-brain scenario (dual masters) typically occurs when VRRP advertisement multicasts cannot reach each other, causing each router to believe the other has failed.
Question 6: Which VRRP priority value is reserved for a router that owns the virtual IP address?
- 0
- 100
- 254
- 255 (Correct answer)
Correct answer: 255
Priority 255 is automatically assigned to the IP address owner (the router whose real IP equals the virtual IP), ensuring it always becomes master.
Question 7: In an Aruba VRRP deployment, what does a VRRP priority value of 0 in an advertisement indicate?
- The router is initializing and not yet ready
- The router is intentionally releasing the master role (Correct answer)
- The router has detected a failure in the virtual router group
- The router's tracking object has decremented priority to zero
Correct answer: The router is intentionally releasing the master role
A VRRP advertisement with priority 0 is sent by the current master to signal that it is voluntarily giving up the master role, prompting an immediate election.
ACSP Virtual Router Redundancy (VRRP) 3
What is the virtual MAC address format used by VRRPv2?