Tracking with using IP SLA?

FrankGuthrie

I was wondering if tracking works without the use of IP SLA. If so what are the advantages / disadvantages.

Or is this not possible and are Tracking and IP SLA connected to each other and cannot be used separately? Is IP SLA used to set condition for tracking??

Also when configuring tracking you cannot set the timeout before the threshold. What does the Threshold do and why do you need to configure that first before you can do the timeout, what is there relation? The reason I asked is when I tried to configure a timeout of 2000 I got an error message:

R4(config-ip-sla-echo)#timeout 2000
%Error: timeout is less than threshold 5000

theodoxa

That depends on the protocol. HSRP for example can track an interface (No IP SLA required). IP SLAs allow you to track more than just Interface states. For example, an IP SLA can be used to track the reachability of a web page (HTTP) or Jitter (for Voice Traffic).

FrankGuthrie

But are you saying these are 2 separate process and can be used separately, or can you only use tracking separately and is IP SLA always use in combination of Tracking.

theodoxa

They can be separate (e.g. You could run an IP SLA and simply view the results), though tracking is probably the most common use of an SLA.

cpartin

Threshold is the point at which the SLA is considered failed. Timeout is when it gives up on waiting for a response. Say you had a ping SLA set to threshold 150, timeout 500. A ping with a RTT of 175ms would trigger a fail, but you'd still get collect statistics on the response. Any response over 500ms would simply be discarded.