This test verifies OpenConfig configuration and telemetry for interface-level egress sFlow sampling, as well as the receipt and structure of egress-sampled flow records on an external sFlow collector.

While standard sFlow sampling captures packets at the ingress pipeline, egress sFlow enables sampling of packets as they egress the device (after header modifications, routing, and encapsulation). This test verifies that:

1. Interface-level egress-sampling-rate can be configured via OpenConfig gNMI.
2. The operational state for egress-sampling-rate and interface enabled reflect correctly in telemetry.
3. Transmitted traffic through the configured egress interface generates valid sFlow datagrams sent to the collector.
4. Captured flow samples correctly identify the sampled egress interface.

• featureprofiles/topologies/atedut_2.testbed

+------------+                 +------------+
|            |  Port 1 (Ing)   |            |
|            |-----------------|            |
|    ATE     |                 |    DUT     |
|            |  Port 2 (Egr)   |            |
|            |-----------------|            |
+------------+                 +------------+

• DUT Port 1: Connected to ATE Port 1 (Ingress traffic source).
• DUT Port 2: Connected to ATE Port 2 (Egress traffic destination & sFlow collector receiver).

1. Configure IP addressing on DUT Port 1 and Port 2 with IPv4 (/30) and IPv6 (/126) subnets.
2. Configure ATE Port 1 and Port 2 with matching IP addresses and verify bidirectional reachability (ARP / NDP resolution).
3. Ensure no prior sFlow configuration exists on the DUT.

{
  "interfaces": {
    "interface": [
      {
        "name": "port2",
        "config": {
          "name": "port2"
        }
      }
    ]
  },
  "network-instances": {
    "network-instance": [
      {
        "name": "DEFAULT",
        "config": {
          "name": "DEFAULT"
        }
      }
    ]
  },
  "sampling": {
    "sflow": {
      "config": {
        "enabled": true,
        "sample-size": 256
      },
      "collectors": {
        "collector": [
          {
            "address": "192.0.2.2",
            "port": 6343,
            "config": {
              "address": "192.0.2.2",
              "port": 6343,
              "source-address": "192.0.2.1",
              "network-instance": "DEFAULT"
            }
          }
        ]
      },
      "interfaces": {
        "interface": [
          {
            "name": "port2",
            "config": {
              "name": "port2",
              "enabled": true,
              "egress-sampling-rate": 1000000
            }
          }
        ]
      }
    }
  }
}

• Step 2 - Push configuration to DUT using gNMI.Set (Update/Replace).
• Step 3 - Verify Telemetry using gNMI.Get or gNMI.Subscribe:
  • /sampling/sflow/state/enabled is true.
  • /sampling/sflow/collectors/collector[address=192.0.2.2][port=6343]/state/address matches 192.0.2.2.
  • /sampling/sflow/interfaces/interface[name=port2]/state/enabled is true.
  • /sampling/sflow/interfaces/interface[name=port2]/state/egress-sampling-rate matches 1000000 (or the configured rate).

• Step 1 - Traffic Generation:

  • Configure ATE Port 1 to transmit IPv4 and IPv6 traffic towards destinations reachable via DUT Port 2.
  • Set traffic rate high enough to generate statistically meaningful samples based on the configured sampling rate (e.g. 100,000 pps for 1,000,000 sampling rate over 60–120 seconds).
  • Start sFlow packet capture on ATE Port 2 listening on UDP port 6343.

• Step 2 - Telemetry and Packet Verification:

  • Verify that sFlow datagrams (UDP port 6343) arrive at ATE Port 2 from source IP 192.0.2.1.
  • Parse captured sFlow datagrams and verify:
    • sFlow version is 5.
    • Agent address matches the configured source IP address (192.0.2.1).
    • Flow sample records are present.
    • In the flow record, the output interface (output_interface / egress interface index) matches the SNMP ifIndex of DUT Port 2.
    • The number of captured samples conforms to the expected sampling rate within statistical tolerance (e.g. ±20%).

• Step 1 - Disable Configuration:

  • Remove egress-sampling-rate from DUT Port 2, or set /sampling/sflow/interfaces/interface[name=port2]/config/enabled to false.

• Step 2 - Telemetry and Traffic Verification:

  • Verify telemetry reflects the disabled state.
  • Transmit traffic from ATE Port 1 to ATE Port 2 and confirm no further sFlow sample datagrams are generated or exported by the DUT.

paths:
  ## Config Parameter Coverage
  /sampling/sflow/config/enabled:
  /sampling/sflow/config/sample-size:
  /sampling/sflow/collectors/collector/config/address:
  /sampling/sflow/collectors/collector/config/port:
  /sampling/sflow/collectors/collector/config/source-address:
  /sampling/sflow/collectors/collector/config/network-instance:
  /sampling/sflow/interfaces/interface/config/name:
  /sampling/sflow/interfaces/interface/config/enabled:
  /sampling/sflow/interfaces/interface/config/egress-sampling-rate:

  ## Telemetry Parameter Coverage
  /sampling/sflow/state/enabled:
  /sampling/sflow/state/sample-size:
  /sampling/sflow/collectors/collector/state/address:
  /sampling/sflow/collectors/collector/state/port:
  /sampling/sflow/collectors/collector/state/source-address:
  /sampling/sflow/collectors/collector/state/network-instance:
  /sampling/sflow/interfaces/interface/state/name:
  /sampling/sflow/interfaces/interface/state/enabled:
  /sampling/sflow/interfaces/interface/state/egress-sampling-rate:

rpcs:
  gnmi:
    gNMI.Set:
    gNMI.Subscribe: