3 Replies Latest reply on Jun 25, 2014 8:20 PM by superfly99

    What Dependencies are Implicit?

    philip.mayo

      We just got SolarWinds NPM for our network.  Our network is full of WAN dependencies, so I am setting them up, but I need some clarification.  Before I create a bunch of unnecessary dependencies, I need to know what are already implicit?  What Nodes and Interfaces will automatically become Unreachable without an explicitly defined dependency?  It is a live network, so I do not have the freedom to experiment to derive my own answers.

       

      If a node is set to Unreachable as the member of a Child group whose dependency has been triggered:

      1. Do the interfaces of that same node also become Unreachable?
      2. Do the dependencies for which that node is a Parent also trigger?
      3. Do the dependencies for which any interfaces of that node happen to be Parents also trigger?

       

      Thanks,

      Phil.

        • Re: What Dependencies are Implicit?
          superfly99

          The only implicit dependency is the interfaces. So when a node goes down, the interfaces are marked as unreachable and you'll only get a notification for the node going down. This is automatic. The rest of the dependencies you need to create.

           

          If a node is a parent for other nodes and it goes down, the other nodes will be marked as unreachable (inc the interfaces) and you'll only get a notification for the parent.

           

          I hope that answers your questions.

          1 of 1 people found this helpful
            • Re: What Dependencies are Implicit?
              philip.mayo

              superfly99 wrote:

              If a node is a parent for other nodes and it goes down, the other nodes will be marked as unreachable (inc the interfaces) and you'll only get a notification for the parent.

              You answered my first breakdown.  I need deeper clarification on the dependency hierarchy.

               

              My dependency parents are not nodes, but normally groups of interfaces, or a single interface, the children of which are nodes.  I am asking if the child nodes' interfaces are included (which you answered I think), and any dependency for those interfaces from that secondary node also included.

               

              Here is an example of one set of dependencies:

               

              Parent A - group of interfaces (GRE tunnels) - all must go down (worst) for isolation

              Child A - group of nodes dependent on those tunnels

               

              Parent B - interface on a node from Child A group

              Child B - another node not already included in Child A group

               

              If all the interfaces in Parent A group go down, triggering the first dependency--I have your answer that the interfaces for Child A nodes would also become unreachable--does the node of Child B (and, I assume, its interfaces) also become unreachable?  Should I include the Child B node in the Child A group, or do the dependencies cascade correctly?

               

              Would this cascade to a further dependency?

               

              Thanks,

              Phil.

                • Re: What Dependencies are Implicit?
                  superfly99

                  If Parent A goes down, then Child A would become unreachable. And Child B will also become unreachable as Parent B has become unreachable due to Parent A going down.

                   

                  If Parent A goes down, then all the interfaces on Child A and Child B will also become unreachable. This dependency is automatic.

                   

                  Hope that helps.