IP SLA with Boolean & HSRP

[dcanady55]

Hello,

I don't have a way to lab up my question unfortunately and was hoping to get some feedback if this is correct. Currently, I have the IP SLA 1 in production and that's working with my HSRP and if the track object fails to respond to pings, then then my priority decrements by 20 causing my standby router to become active. This worked as designed when I tested it. I'm looking to solve for another failover scenario and need to track another object. Would it be best to create a track 3 boolean using the "and" statement as I do want HSRP to decrement by 20 in either case or can I simply add the following line under my gig 0/0/2 interface "standby 1 track 2 decrement 20" ? 

Thanks

ip sla 1
icmp-echo 192.168.73.2 source-interface GigabitEthernet0/0/0
frequency 10
ip sla schedule 1 life forever start-time now
i

p sla 2
icmp-echo 10.172.21.2 source-interface GigabitEthernet0/0/0
frequency 10
ip sla schedule 2 life forever start-time now

interface GigabitEthernet0/0/2
ip address 192.168.73.9 255.255.255.248
standby 1 ip 192.168.73.11
standby 1 priority 200
standby 1 preempt
standby 1 track 1 decrement 20
load-interval 30
media-type sfp
negotiation auto

track 1 ip sla 1 reachability
!
track 2 ip sla 2 reachability
!
track 3 list boolean and
object 1
object 2

[MHM Cisco World]

MHM

[MHM Cisco World]

MHM

[David Ruess]

Hello,

Either way is fine. If you are creating rules to affect the same HSRP process then I would just keep them together with a boolean. However, it would need to be an OR AND if you want EITHER case to affect the HSRP process. AND means BOTH have to be upn before it decrements.

With this design it looks like you can do this:

interface GigabitEthernet0/0/2
ip address 192.168.73.9 255.255.255.248
standby 1 ip 192.168.73.11
standby 1 priority 200
standby 1 preempt
standby 1 track 3 decrement 20
load-interval 30
media-type sfp
negotiation auto

track 1 ip sla 1 reachability
!
track 2 ip sla 2 reachability
!
track 3 list boolean and
object 1
object 2

-David

[dcanady55]

Thanks for the feedback as MHM and you say the opposite. I will test in next week's maintenance window and report back. 

[MHM Cisco World]

Thanks 

MHM

[dcanady55]

You said AND is equal to any of the objects being down which is what I read in a few other articles. David said AND is equal to both objects going down. I am looking to track if either of the objects go down. 

[David Ruess]

If you're looking for EITHER then the Boolean you would use in this case is OR. In your case it may be AND as @MHM Cisco World suggested. I will try to lab and make sure.

[MHM Cisco World]

MHM

[David Ruess]

Ah. I believe you are correct. I was just going by the normal boolean logic. I was going to lab this later also and see the results. I may have t mixed up.

[David Ruess]

I did have it mixed up. After labbing @MHM Cisco World is correct in that a boolean AND will need to be configured for a Track 3. It states this link AND this link must be up to meet the requirement and keep the UP status.

[MHM Cisco World]

MHM

[MHM Cisco World · Accepted solution]

to summary this topic for you and later for anyone see this post 
-in HSRP we use the track number of parent 
- in HSRP the track down status is effect the priority  

% Boolean AND parent track is UP when both child track is UP  
% Boolean AND parent track is Down when ANY child track is Down <<<-

% Boolean OR parent track is UP when ANY child track is UP  
% Boolean AND parent track is Down when Both child track is Down <<<-