Re: IP Sla with boolean

Haris P · ‎12-22-2010

Dears ,

Im trying to do IP SLA for failover between 2 WAN links, when i put show trck the object 33 is coming as undefined ? why like this ? Do u have any document for IPS SLA config with boolean expression ?

The below is config

track 1 ip route 0.0.0.0 0.0.0.0 reachability
!
track 25 list boolean and
object 1
object 33

ip sla 33
icmp-echo 192.168.111.105 source-ip 192.168.111.106
timeout 1000
threshold 250
ip sla schedule 33 life forever start-time now

_____________________________________________

show track
Track 25
List boolean and
Boolean AND is Up
    4 changes, last change 23:58:43
    object 1 Up
    object 33 (Undefined)
Tracked by:
    STATIC-IP-ROUTING 0

Regards

rasagi · ‎12-30-2010

Hi Harris,

A standard failover IP SLA configuration should look like this.

Assuming primary and secondary link are Gi 0/0 and Gi 0/1 with next hop ip addresses as 10.0.0.2 and 11.0.0.2 respectively.

track 1 ip sla 1 reachability
!
ip sla 1
icmp-echo 10.0.0.2 source-interface GigabitEthernet 0/0
threshold 1000

timeout 1000
ip sla schedule 1 life forever start-time now
!

ip route 0.0.0.0 0.0.0.0 10.0.0.2 1 track 1
ip route 0.0.0.0 0.0.0.0 11.0.0.2 2

When reachability to 10.0.0.2 is up, track 1 is up and default route with admin distance 1 is used. When reachability to 10.0.0.2 is down, track 1 is down and first default route will be invalid and default route with admin distnace 2 will be used.

Some times you want to test reachability to internet and not just the next hop. In that case you can setup the IP SLA oepration to a public dns server. Also the above configuration will fail over for even a single drop of icmp-echo packets sent by the ip sla operation. You can make the failover more robust by letting 3 consecutive ip sla operations to fail before the failover happens. Config with these changes is given below.

track 1 ip sla 1 reachability

delay down 30 up 30
!
ip sla 1
icmp-echo 4.2.2.2 source-interface GigabitEthernet 0/0
threshold 1000

timeout 1000

frequency 10
ip sla schedule 1 life forever start-time now
!

ip route 0.0.0.0 0.0.0.0 10.0.0.2 1 track 1
ip route 0.0.0.0 0.0.0.0 11.0.0.2 2

A couple of good reference links for IP SLA configuration and track configuration are given below.

http://www.cisco.com/en/US/docs/ios/12_4/ip_sla/configuration/guide/hsicmp.html

http://www.cisco.com/en/US/docs/ios/ipapp/configuration/guide/ipapp_eot.html

I would advise implementing configurations on lab devices before implementing in production environments.

Thank you.

PS: Please open up any future queries regarding IP SLA under the 'Network Management' Comminuty instead of 'LAN, switching and routing'. If you have any further questions I would advise you to copy this same thread onto a new thread in the 'Network Management' community.

Regards,

Rahul Sagi

fabiossilva · ‎04-04-2014

it is undefined because you need to add a track like this

track 33 ip sla 33 reachability

and after that you can reference on the boolean list