Greetings.

On one CISCO device we have a defined failover, in which a secondary VPN tunnel is activated if and when the primary tunnel fails.

Both tunnel interfaces are defined by their custom SNMP OID's, in a "snmplibrarysensor" type sensor.

Since only one of the tunnels is active at one instance, the second tunnel sensor will always be in a Down state with message "No such instance (SNMP error # 223)". This forces us to always Acknowledge the sensor manually.

We would like to have a single sensor(or two) that would change it's state depending on the current state of the tunnel interfaces, and being in the Down state only if both tunnels are down.

Article Comments

Hello Hrvoje,

Thank you for your KB-post.

You can create the Sensor Factory Sensor that will go down only when both the sensor X and the sensor Y are down.

You can configure it in the following way:

1. Check the ID numbers of the sensor X and the sensor Y.

2. Create new Sensor Factory Sensor. In the Settings of the sensor it is necessary to define the channels, based on another sensors. This is the example of the Channel Definition:

#1:test1
Channel(2005,0)

#2:test2
Channel(2008,0)

In this example, 2005 is the ID of the sensor X, and 2008 is the ID of the sensor Y, and 0 is the channel ID within the sensor.

3. In the option "Error Handling" please choose "Use custom formula" and type the following:

status(2005) AND status(2008)

Using this formula, the "Sensor Factory Sensor" will get into an error state only if both the sensor X (ID 2005) and the sensor Y (ID 2008) are down.

Best regards


Aug, 2016 - Permalink

Hello.

This is a good definition, sensor factory will solve one part of the issue.

But, this entails that we still need to have these two sensors defined on the device, and that those sensor will show a "Down" state when unused, and raise an unnecessary alarm.


Aug, 2016 - Permalink

Hello,

I am afraid there is no workaround for this - it is not possible to avoid one sensor being down in such case, sorry.

Best regards


Aug, 2016 - Permalink