Path Outages

An outage of a central network component can cause a lot of node outages. Path Outages can be used to suppress Notifications based on how Nodes depend on each other in the network which are defined in a Critical Path. The Critical Path needs to be configured from the network perspective of the monitoring system. By default the Path Outage feature is disabled and has to be enabled in the poller-configuration.xml.

The following image shows an example network topology.

02 path outage
Figure 1. Path Outage example

From the perspective of the monitoring system, a Router named default-gw-01 is on the Critical Path to reach two networks. If Router default-gw-01 is down, it is not possible to reach any node in the two networks behind and they will be all unreachable as well. In this case an administrator would like to have just one notification for default-gw-01 and not for all the other Nodes behind. Building this configuration in Meridian requires the following information:

  • Parent Foreign Source: The Foreign Source where the parent node is defined.

  • Parent Foreign ID: The Foreign ID of the parent Node where this node depends on.

  • The IP Interface selected as Primary is used as Critical IP

In this example we have created all Nodes in a Provisioning Requisition named Network-ACME and we use as the Foreign ID the same as the Node Label.

In the Web UI go to Admin → Configure OpenNMS → Manage Provisioning Requisitions → Edit the Requisition → Edit the Node → Path Outage to configure the network path by setting the Parent Foreign Source, Parent Foreign ID and Provisioned Node.

Table 1. Provisioning for Topology Example
Parent Foreign Source Parent Foreign ID Provisioned Node

not defined

not defined

default-gw-01

Network-ACME

default-gw-01

node-01

Network-ACME

default-gw-01

node-02

Network-ACME

default-gw-01

default-gw02

Network-ACME

default-gw-02

node-03

Network-ACME

default-gw-02

node-04

The IP Interface which is set to Primary is selected as the Critical IP. In this example it is important the IP interface on default-gw-01 in the network 192.168.1.0/24 is set as Primary interface. The IP interface in the network 172.23.42.0/24 on default-gw-02 is set as Primary interface.