FHRP

Question 1

What are the 3 FHRPs for the CCNA?

Answer 1

• HSRP (Hot Standby Router Protocol)
• VRRP (Virtual Router Redundancy Protocol)
• GLBP (Gateway Load Balancing Protocol)

Question 2

What is an FHRP?

Answer 2

A protocol used to protect the default gateway of a subnet by allowing two or more routers to provide backup for that address

Question 3

Two or more routers share a _____, and PCs configure this as their default gateway

Answer 3

VIP

Virtual IP

Question 4

In addition to a VIP, two FHRP routers share a ____

Answer 4

VMAC, virtual MAC

Question 5

How do routers determine their role in an FHRP protocol?

Answer 5

By sending multicast hello messages to eachother

Question 6

How does an FHRP provide a host with the MAC of the active default gateway router?

Answer 6

By using ARP

The active router sends an ARP reply, while the standby ignores the message

Question 7

How does an FHRP standby router change to an active router if the previous active router fails?

Answer 7

Gratuitous ARP

The new active router sends a gratuitous ARP message to broadcast, and all hosts update their MAC address for the default gateway IP to the new one.

Question 8

When does an FHRP standby router change to an active?

Answer 8

After a standby router hasn’t received any hello messages for a duration of time.

By default 10 seconds, else 3 times the hello timer

Question 9

What is a gratuitous ARP message?

Answer 9

An ARP reply sent without an ARP request triggering it. Sent broadcast.

Question 10

By default, are FHRPs preemptive or non-preemptive

Answer 10

Non-preemptive by default

Question 11

Which FHRP would use the VMAC 0000.5E00.0101?

Answer 11

VRRP

VRRP VMACs are of the form 0000.5E00.01xx, where the xx is the hex value of the group number.

Question 12

Which FHRP would use the VMAC 0000.0C9F.F001

Answer 12

HSRP

HSRPv2 VMACs are of the form 0000.0C9F.Fxxx

Question 13

Which FHRP would use the VMAC 0000.0C07.AC01

Answer 13

HSRP

HSRPv1 VMACs are of the form 0000.0C07.ACxx

Question 14

What FHRP would use the VMAC 0007.B400.0101

Answer 14

GLBP

GLBP VMACs are of the form 0007.B400.xxyy, where xx is the GLBP group number, and yy is the AVF number

Question 15

What FHRP would use the IP address 224.0.0.2

Answer 15

HSRPv1

Question 16

What FHRP would use the IP address 224.0.0.102

Answer 16

HSRPv2
GLBP

Both use the same multicast IPv4, but GLBP uses a different port than HSRP

Question 17

What FHRP would use the IP address 224.0.0.18

Answer 17

VRRP

Question 18

What FHRP has a single active virtual gateway and up to 4 active virtual forwarders for a single group?

Answer 18

GLBP

Each AVF is assigned to a portion of hosts in the subnet by the AVG, therefore gateway traffic is load balanced across multiple devices

Question 19

Routers in which HSRP states send hello messages?

Answer 19

Active, standby, speaking

Question 20

Routers in which HSRP states listen for hello messages from the active router?

Answer 20

Standby, listening

Question 21

Does HSRP support multiple routers in the standby state?

Answer 21

Technically no, but functionally yes

Only one router can have the standby state. If the active fails, the standby becomes the active, and then a new standby is elected from other routers in the listening state.