Day 24 - HSRP Flashcards
What does FHRP stand for?
First Hop Redundancy Protocol
What is FHRP?
A first hop redundancy protocol which is designed to protect the default gateway used on a network by allowing two or more routers to provide backup for it
What is the most popular FHRP?
HSRP (Hot Standby/Swap Router Protocol)
With HSRP, do the routers being used with the protocol have actual IP addresses on their physical links?
Yes
How are HSRP routers elected under a normal configuration?
The highest IP Address of the physical interfaces being used will be elected as Active. The lowest will be the standby.
How do both routers make sure that the other one is still up?
They send Keep Alive Hellos
How does a Standby Router become an Active Router
A keep alive hello wasn’t responded to so the Standby router will assume the role of Active
What is a virtual IP address on a HSRP router?
It is the Virtual IP Address configured on both routers to act as a default gateway that never goes down
Where does all traffic bound for the Virtual IP go?
Through the Active Router
What is a genericconfiguration for an HSRP Router?
R1(config)#int {int}
R1(config-if)#ip address {ip-address} {subnet-mask}
R1(config-if)#no shut
R1(config-if)#standby 1 ip {ip-address}
What is the default priority on routers for HSRP?
100
When a higher priority router comes back online after a failure it will transition back to Active when what is enabled?
Pre-emption
Is Pre-Emption enabled by default?
No
The lower priority router will remain the active router when the failed router comes back online when this is not enabled on the router
Pre-emption
How do you configure a priority and pre-emption on a router?
int {int}
R1(config-if)#standby 1 priority {priority}
R1(config-if)#standby 1 preempt
How many versions of HSRP are there?
2
How do you enable HSRP Version 2?
int {int}
R1(config-if)#standby version 2
How do you verify HSRP?
show standby
__________ enables you to install multiple routers in a subnet to collectively act as a single default router
FHRP (First-Hop Redundancy Protocol)
FHRP routers share a virtual what?
IP address
The capability of a network to dynamically recover from the failure of a device acting as a default gateway is known as what?
First-hop redundancy
What 3 options are available for FHRPs?
HSRP (Hot Standby Router Protocol)
VRRP (Virtual Router Redundancy Protocol)
GLBP (Gateway Load Balancing Protocol)
HSRP active router implements what two virtual items?
IP address
MAC address
What must an HSRP virtual IP address be apart of to be a sound configuration?
The same subnet as the physical interface IP address
If a router goes down and another takes over, what must the new active router do to get the switches on the subnet to change their MAC address tables to reflect the correct port to reach the virtual MAC?
Send a gratuitous ARP
If you configured the priority of an HSRP router to have a priority of 90 over the default priority, would it be the active router?
No, because the priority would need to be higher than 100 to take on the preferred active role
What would you command be to change the priority of an HSRP router considering the priority is in it’s default state of 100
standby 1 priority 110
