Cisco SX350 Series Administration Manual page 431

IP Configuration: SLA
Overview
Cisco Sx350, SG350X, SG350XG, Sx550X & SG550XG Series Managed Switches, Firmware Release 2.2.5.x
A track object status can be used by various applications in decisions that require knowledge
of network connectivity. One example of such an application is VRRP. The track object is
assigned to a VRRP router. If track status is down, the VRRP priority of router is decremented
by a value defined by user. If track status is up, the original VRRP priority of router is
maintained.
The following describes the main terms used in this section:
• Operation—Each IP SLAs ICMP Echo operation sends a single ICMP Echo request
to a target address at a configured frequency rate. It then waits for a response.
• Track Object State—Each tracking object maintains an operation state. The state is
either: Up or Down. After object creation, the state is set to Up. The following table
specifies the conversion of the IP SLAs operation return code to the object state:
Operation Return Code
OK
Error
If the IP SLAs operation specified by the track argument is not configured or is
NOTE
its schedule is pending, its state is OK.
An application that is bound to a non-existing tracking object will receive the Up
NOTE
state.
• SLA Operation State—This can be either Scheduled, which means the operation
begins immediately or Pending, which means it has been created but not activated.
• Timeout value —Specifies the interval time of waiting for the ICMP echo reply
message or an ICMP error message.
• Return Code—After an operation has been finished the operation return code is set
according to the following:
- ICMP Echo reply has been received—Return code is set to OK.
- ICMP Error reply has been received—Return code is set to error.
- No any ICMP reply has been received—Return code is set to error.
- Configured Source IP address or Source interface is not accessible—Return code is
set to error.
• Tracker—Tracks the results of operations.
Track Operation State
Up
Down
19
418