ACSP Virtual Router Redundancy (VRRP) 4 — Questions and Answers
Question 1: A network administrator wants to use two VRRP groups on the same VLAN to achieve load balancing. How is this accomplished?
- Configure VRRP with built-in load-balancing mode enabled
- Create two VRRP groups with different VRIDs; make each router master of one group (Correct answer)
- Set both routers to priority 128 in the same VRRP group
- Enable ECMP within the VRRP group configuration
Correct answer: Create two VRRP groups with different VRIDs; make each router master of one group
Load balancing with VRRP is achieved by running two VRRP groups with different VRIDs, configuring each router as master of one group, and splitting hosts between the two virtual gateways.
Question 2: Which multicast address does VRRPv2 use to send advertisement messages?
- 224.0.0.1
- 224.0.0.2
- 224.0.0.18 (Correct answer)
- 224.0.1.1
Correct answer: 224.0.0.18
VRRPv2 sends advertisement packets to the multicast group 224.0.0.18 using IP protocol number 112.
Question 3: On an Aruba switch, which of the following is the correct sequence to add VRRP tracking for an uplink interface?
- Define track object → apply track object to VRRP group with priority decrement (Correct answer)
- Apply VRRP group → enable tracking globally → configure decrement
- Configure VRRP priority → enable object tracking → bind by VLAN
- Enable VRRP preemption → add tracked interface → set advertisement interval
Correct answer: Define track object → apply track object to VRRP group with priority decrement
The correct process is to first define the tracking object (e.g., track interface or IP SLA), then reference it in the VRRP group configuration with a priority decrement value.
Question 4: What IP protocol number is used by VRRP packets?
- 89
- 97
- 112 (Correct answer)
- 115
Correct answer: 112
VRRP uses IP protocol number 112, which identifies VRRP packets at the network layer.
Question 5: In a VRRP deployment on Aruba switches, what is the effect of configuring a very short advertisement interval?
- It increases the master-down interval, slowing failover
- It reduces the master-down interval, enabling faster failover detection (Correct answer)
- It disables preemption to prevent instability
- It increases CPU overhead without affecting failover speed
Correct answer: It reduces the master-down interval, enabling faster failover detection
A shorter advertisement interval reduces the master-down timer calculation, allowing backup routers to detect master failure more quickly and take over faster.
Question 6: Which authentication type is supported by VRRPv2 but was deprecated in VRRPv3?
- SHA-256 HMAC
- MD5 keyed hash
- Simple text (plain-text) password (Correct answer)
- PKI certificate-based authentication
Correct answer: Simple text (plain-text) password
VRRPv2 supported simple text (Type 1) and MD5 (Type 2) authentication, but both were deprecated in VRRPv3 as RFC 5798 does not include VRRP authentication.
Question 7: An Aruba switch running VRRP shows a router stuck in the INIT state. What is the most likely reason?
- The VRRP group priority is set to 255
- The VLAN or IP address is not properly configured on the interface (Correct answer)
- The advertisement interval is set to maximum
- Preemption is disabled on the interface
Correct answer: The VLAN or IP address is not properly configured on the interface
A VRRP router remains in INIT state when the associated VLAN interface is not up or the IP address is missing, preventing the VRRP state machine from progressing.
ACSP Virtual Router Redundancy (VRRP) 4
A network administrator wants to use two VRRP groups on the same VLAN to achieve load balancing.
How is this accomplished?