FHRP Flashcards
3 major FHRP protocols
- HSRP2. VRRP3. GLBP
What does GLBP stand for?
Gateway Load Balancing Protocol
What does FHRP stand for?
First Hop Redundancy Protocol
What does VRRP stand for?
Virtual Router Redundancy Protocol
What does HSRP stand for?
Hot Standby Router Protocol
How does HSRP implement loadbalancing?
By allowing different routers be the active router for different subnets.
What’s the biggest difference between GLBP and HSRP/VRRP?
GLBP uses an active/active model, so traffic can be distributed between multiple routers even if the hosts are in the same subnets.
What function does the AVG perform?
In GLBP, the AVG replies to all ARP requests for the virtual IP address. It will LB the responses so that the hosts end up balanced between all the routers in the group.
What does AVG stand for?
Active Virtual Gateway
How does the AVG direct hosts to utilize different routers as their gateways?
By providing the MAC addresses of different routers in the LB group for the virtual IP address.
HSRP syntax to set up the VIP for a LB group
conf tinterface gi1/0standby group # ip VIP
5 basic HSRP attributes that can be configured under an interface
- VIP2. Group name3. Priority4. Version5. Preempt
HSRP syntax to set priority for a LB group
conf tinterface gi1/0standby group # priority priority value
For HSRP, what is the default priority?
100
For HSRP, what is the priority range?
1 - 255
For HSRP, is a higher or lower priority better?
Higher
HSRP syntax to return an interface to active state after it comes back up
conf tinterface gi1/0standby group # preempt
2 commands to show detailed HSRP status
show standbyshow standby brief
GLBP syntax to configure the virtual IP
glbp group # ip vip
GLBP syntax to configure the name of the LB group
glbp group # name name
How does GLBP’s priority system differ from that of HSRP?
It doesn’t. Same defaults and priority range, along with the fact that higher priority is better.
How does a router become a GLBP AVG?
It has the higher priority and either comes online first, or has preemption enabled.
2 commands to show the status of GLBP
show glbp show glbp brief
What is the GLBP term for a router that is active in a LB group?
A forwarder
