Count of Received IPv4 Unicast Prefixes

Work in Progress

RBMS is currently under active development. Features, APIs, and behavior may change without notice. It is not recommended for production use at this stage.

Sampling the number of received unicast prefixes is an example for an index based metric. The IPv4 unicast prefixes are stored in the instance.default.ribd.1.fib-local.ipv4.labeled-unicast table, which exists per routing instance with instance being the instance name. The prefix count can be read by sampling the active-entry-count attribute of the primary index. The listing below shows the JSON object to sample the active PPPoE sessions:

Listing 15 - JSON object to enable PPPoE session count sampling

{
    "rtbrick-config:metric": {
        "name": "default_ipv4_unicast_prefix_count",
        "table-name": "default.ribd.1.fib-local.ipv4.unicast",
        "bds-type": "index-metric",
        "index-name": "primary",
        "prometheus-type": "gauge",
        "description": "IPv4 unicast prefixes default instance",
        "attribute": [
            {
                "attribute-name": "active-entry-count"
            }
        ]
    }
}

The prefix count can increase and decrease. Therefore the metric type must be gauge rather than counter.

Run show datastore ribd schema table table-name default.ribd.1.fib-local.ipv4.unicast to inspect the definition of the default.ribd.1.fib-local.ipv4.unicast table.

Listing 16 - Excerpt of the table definition CLI output

$ show datastore fibd schema table-name default.ribd.1.fib-local.ipv4.labeled-unicast
{
  "table": {
    "type": "rib_fiblocal_v4_table",
    "object": "rib_entry",
    "table_objects": {
      "shared_object": "generic_table_attributes",
      "app_objects": [
        "generic_table_attributes"
      ]
    },
    "index": [
      {
        "name": "primary",
        "type": "radix",
        "immutable": true,
        "key": [
          "prefix4"
        ]
      },
 ...

The primary index uses the IPv4 prefix (prefix4) as key and contains an object per prefix. Counting the objects therefore represents the stored prefixes.