In this section:
The Link Monitor object allows you to monitor a link for a specific interface and belongs to a link detection group.
A new Link Monitor is created for each interface that is configured for link verification. The Link Monitor is provided with a destination to use for link verification as well as the Link Detection Group to which it belongs. The Link Monitor is responsible for pinging that destination, processing responses and determining when the interface should be considered failed. It reports such failures to its Link Detection Group. You must configure link monitors for the active and standby SBC with different destinations, to avoid a failure scenario where the active and standby SBC fail back and forth due to link detection failures caused by loss of communication with a single destination. The active and standby SBC should be connected to different physical hardware (that is, switches) to avoid a single point of failure.
Each Link Monitor that is configured can also be configured with unique values for the Verify Timer
, Response Timer
, Reattempt Timer
, and Maximum Retries
. If configured, these values override the values configured for the Link Detection Group.
Each Link Monitor will set a timer while waiting to perform its next verification. The timeout for this timer is based on the configured Verify Timer
value. When a ping is in progress and the Link Monitor is awaiting the response from the destination, a timer is set based on the configured Response Timer
value. When the response times out and the Link Monitor retries, the Reattempt Timer
value is used while waiting for the response.
When the number of consecutive failures reaches the Maximum Retries
value, the Link Monitor considers the link verification as failed and reports this to its Link Detection Group.
While in the failed state, the Link Monitor will continue to attempt to ping the destination so that the failed condition can eventually clear. This is done at the rate specified by the Verify Timer
.
The Link Monitor also supports a NULL destination (0.0.0.0), which disables the link verification for that interface. The interface is still considered failed if there is a hardware failure.
Link Monitor verifies transport on a specific interface via Layer 3 ICMP/ARP/NUD to a specific destination or monitors MII state for the physical port, where MII is defined as “Media Independent Interface”.
On SBC main screen, go to Configuration > System Provisioning > Category: Base Provisioning > Link Detection Group > Link Monitor. The Link Monitor window is displayed.
The Link Monitor can be checked for each Address Context or for each Link Detection Group or for all the Address Contexts and Link Detection Groups created. Use the drop-down box to select the desired Address Context and Link Detection Group.
To edit any of the Link Monitors in the list, click the radio button next to the specific Link Monitor name.
The Edit Selected Link Monitor window is displayed below.
Make the required changes and click Save at the right hand bottom of the panel to save the changes made.
To create a new Link Monitor, click New Link Monitor tab on the Link Monitor List panel.
The Create New Link Monitor window is displayed.
The following fields are displayed:
To copy any of the created Link Monitor and to make any minor changes, click the radio button next to the specific Link Monitor to highlight the row.
Click Copy Link Monitor tab on the Link Monitor List panel.
The Copy Selected Link Monitor window is displayed along with the field details which can be edited.
Make the required changes to the required fields and click Save to save the changes. The copied Link Monitor is displayed at the bottom of the original Link Monitor in the Link Monitor List panel.
To delete any of the created Link Monitor, click the radio button next to the specific Link Monitor which you want to delete.
Click Delete at the end of the highlighted row. A delete confirmation message appears seeking your decision.
Click OK to remove the specific Link Monitor from the list.