Components that you must configure for path monitoring.

You can combine these components in various ways to build simple or complex routing decision flows.

Path monitor host

You must configure at least one path monitor host. A path monitor host is a collection of parameters that define the following:

• The IP address or domain name of the target host. A path monitor monitors the path to the target host.
• The monitor type. Vyatta supports both ping and TWAMP.

Optionally, you can specify a DSCP value to tag the monitor packets. The DSCP directs the ping traffic to use the same QoS that is in use for the traffic on the monitored link. If you do not specify a DSCP value, the monitor traffic might receive different treatment in transit, which results in unrepresentative or meaningless measurements.

Path monitor policy

You must configure at least one path monitor policy. A path monitor policy is a collection of parameters that define whether or not the monitoring results comply with the policy.

Path monitor

You must configure at least one path monitor instance.

A path monitor instance is an association between a path monitor host, a context (a source interface or a routing instance), and one or more path monitor policies.

Compliance is considered on a one-to-one basis between a path monitor instance and each of its associated policies. A Path monitor instance probes a path monitor host and measures various characteristics, such as round-trip time (RTT). If all measurements are within the threshold defined by the associated path monitor policy, then the path complies with the policy.

Routing instances

We recommend that you configure routing instances that isolate the traffic of each path. Routes in these instances can be statically or dynamically learned.

PBR policy

To route traffic based upon path performance, you must configure at least one PBR policy. This is not required if you want only a passive path.