interface_admin_drain_test

RT-5.17: Physical Interface Drain via Admin Down

Summary

Validates that setting a physical interface's administrative state (enabled) to false via gNMI causes associated routing protocols (BGP peering sessions and IS-IS Level-2 adjacencies) to tear down cleanly, ceases all traffic forwarding across the drained interface, and ensures pass-through traffic across non-drained interfaces remains completely unaffected. Furthermore, validates that re-enabling the interface restores routing protocol sessions and traffic forwarding.

Testbed type

• https://github.com/openconfig/featureprofiles/blob/main/topologies/atedut_4.testbed

Topology

               +------------+
  ATE Port 1 --| Port 1     |-- (Drained Physical Interface Under Test)
  ATE Port 2 --| Port 2 DUT |-- (Ingress Traffic Generator Port)
  ATE Port 3 --| Port 3     |-- (Pass-through / Egress Port)
  ATE Port 4 --| Port 4     |-- (Auxiliary Transit / Monitoring Port)
               +------------+

• DUT Port 1 (Drained Interface): Connected to ATE Port 1.
  • Network Instance: DEFAULT
  • IPv4: 198.51.100.1/31, IPv6: 2001:db8:1::1/127
  • ATE IPv4: 198.51.100.0/31, ATE IPv6: 2001:db8:1::0/127
  • BGP Peer: eBGP between DUT AS 64500 and ATE AS 64501
  • IS-IS: Level-2 point-to-point adjacency
• DUT Port 2 (Ingress Source): Connected to ATE Port 2.
  • Network Instance: DEFAULT
  • IPv4: 198.51.100.3/31, IPv6: 2001:db8:1::3/127
  • ATE IPv4: 198.51.100.2/31, ATE IPv6: 2001:db8:1::2/127
• DUT Port 3 (Pass-through Egress): Connected to ATE Port 3.
  • Network Instance: DEFAULT
  • IPv4: 198.51.100.5/31, IPv6: 2001:db8:1::5/127
  • ATE IPv4: 198.51.100.4/31, ATE IPv6: 2001:db8:1::4/127
  • BGP Peer: eBGP between DUT AS 64500 and ATE AS 64503
  • IS-IS: Level-2 point-to-point adjacency
• DUT Port 4 (Auxiliary Transit): Connected to ATE Port 4.
  • Network Instance: DEFAULT
  • IPv4: 198.51.100.7/31, IPv6: 2001:db8:1::7/127
  • ATE IPv4: 198.51.100.6/31, ATE IPv6: 2001:db8:1::6/127

Procedure

Test environment setup

1. Establish Layer 3 interface configurations on DUT Ports 1, 2, 3, and 4 with dual-stack IPv4 and IPv6 subnets under the default network instance (DEFAULT).
2. Establish eBGP sessions:
   • DUT Port 1 to ATE Port 1: ATE advertises prefix 203.0.113.0/24 (IPv4) and 2001:db8:2::/64 (IPv6).
   • DUT Port 3 to ATE Port 3: ATE advertises prefix 203.0.113.128/25 (IPv4) and 2001:db8:3::/64 (IPv6).
3. Establish IS-IS Level-2 point-to-point adjacencies over DUT Port 1 and DUT Port 3 with standard metrics.
4. Verify routing protocol session states:
   • /network-instances/network-instance[name=DEFAULT]/protocols/protocol[identifier=BGP][name=bgp]/bgp/neighbors/neighbor[neighbor-address=198.51.100.0]/state/session-state is ESTABLISHED.
   • /network-instances/network-instance[name=DEFAULT]/protocols/protocol[identifier=BGP][name=bgp]/bgp/neighbors/neighbor[neighbor-address=2001:db8:1::0]/state/session-state is ESTABLISHED.
   • /network-instances/network-instance[name=DEFAULT]/protocols/protocol[identifier=BGP][name=bgp]/bgp/neighbors/neighbor[neighbor-address=198.51.100.4]/state/session-state is ESTABLISHED.
   • /network-instances/network-instance[name=DEFAULT]/protocols/protocol[identifier=BGP][name=bgp]/bgp/neighbors/neighbor[neighbor-address=2001:db8:1::4]/state/session-state is ESTABLISHED.
   • IS-IS Level-2 adjacencies on Port 1 and Port 3 are in UP state via /network-instances/network-instance[name=DEFAULT]/protocols/protocol[identifier=ISIS][name=DEFAULT]/isis/interfaces/interface/levels/level[level-number=2]/adjacencies/adjacency/state/adjacency-state.
5. Start continuous bidirectional traffic streams from ATE Port 2:
   • Stream 1: Ingress ATE Port 2 -> Destination 203.0.113.10 / 2001:db8:2::10 (Egress DUT Port 1).
   • Stream 2: Ingress ATE Port 2 -> Destination 203.0.113.130 / 2001:db8:3::10 (Egress DUT Port 3).
6. Verify baseline forwarding: both Stream 1 and Stream 2 experience 0% packet loss at line rate.

RT-5.17.1 - Physical Interface Admin Down Drain

1. Administratively disable DUT Port 1 via gNMI.Set:
   • Set /interfaces/interface[name=port1]/config/enabled to false.

Canonical OC

{
  "openconfig-interfaces:interfaces": {
    "interface": [
      {
        "config": {
          "enabled": false,
          "name": "port1"
        },
        "name": "port1"
      }
    ]
  }
}

2. Validate Interface State via telemetry:

   • /interfaces/interface[name=port1]/state/enabled is false.
   • /interfaces/interface[name=port1]/state/admin-status transitions to DOWN.
   • /interfaces/interface[name=port1]/state/oper-status transitions to DOWN.

3. Validate Routing Protocol Reaction:

   • Verify BGP neighbor sessions over Port 1 (198.51.100.0 and 2001:db8:1::0) transition away from ESTABLISHED (to IDLE or ACTIVE) within the hold-time / fast-down interval.
   • Verify IS-IS Level-2 adjacency on Port 1 transitions to DOWN and is removed from the active IS-IS neighbor table.
   • Verify BGP neighbor sessions and IS-IS adjacencies over Port 3 remain continuously ESTABLISHED and UP without flapping.

4. Validate Data Plane Drain & Pass-Through Traffic Isolation:

   • Verify traffic for Stream 1 (destined to Port 1 prefixes) immediately ceases to egress DUT Port 1; /interfaces/interface[name=port1]/state/counters/out-pkts stops incrementing.
   • Verify pass-through traffic for Stream 2 (destined to Port 3 prefixes) continues forwarding through DUT Port 3 with 0% packet loss and no rate degradation.

5. Pass/Fail Criteria:

   • Pass:
     • DUT Port 1 admin-status and oper-status are DOWN.
     • BGP sessions and IS-IS adjacencies on Port 1 tear down.
     • Forwarding on Port 1 completely ceases.
     • Stream 2 on Port 3 forwards with 0% packet loss and 0 protocol flaps.
   • Fail:
     • DUT Port 1 oper-status remains UP.
     • BGP or IS-IS neighbor sessions over Port 1 remain ESTABLISHED or UP.
     • Packets continue to be transmitted out of Port 1.
     • Pass-through traffic on Port 3 experiences packet loss or session interruption.

RT-5.17.2 - Physical Interface Un-drain and Traffic Restoration

1. Administratively re-enable DUT Port 1 via gNMI.Set:
   • Set /interfaces/interface[name=port1]/config/enabled to true.

Canonical OC

{
  "openconfig-interfaces:interfaces": {
    "interface": [
      {
        "config": {
          "enabled": true,
          "name": "port1"
        },
        "name": "port1"
      }
    ]
  }
}

2. Validate Interface Operational State via telemetry:

   • /interfaces/interface[name=port1]/state/enabled is true.
   • /interfaces/interface[name=port1]/state/admin-status transitions to UP.
   • /interfaces/interface[name=port1]/state/oper-status transitions to UP.

3. Validate Routing Protocol Restoration:

   • Verify BGP neighbor sessions over Port 1 (198.51.100.0 and 2001:db8:1::0) re-establish to ESTABLISHED.
   • Verify IS-IS Level-2 adjacency over Port 1 re-establishes to UP.
   • Verify learned prefixes (203.0.113.0/24 and 2001:db8:2::/64) are re-installed into the FIB.

4. Validate Traffic Flow Recovery:

   • Verify Stream 1 resumes line-rate forwarding across DUT Port 1 with 0% steady-state packet loss.
   • Verify Stream 2 on Port 3 remains stable with 0% packet loss.

5. Pass/Fail Criteria:

   • Pass:
     • DUT Port 1 oper-status returns to UP.
     • BGP neighbor sessions and IS-IS adjacencies on Port 1 return to ESTABLISHED / UP.
     • Stream 1 resumes 100% throughput with 0% steady-state packet loss.
   • Fail:
     • DUT Port 1 remains DOWN.
     • BGP or IS-IS sessions fail to re-establish on Port 1.
     • Forwarding on Port 1 fails to restore or experiences packet loss.

OpenConfig Path and RPC Coverage

The below yaml defines the OC paths and RPCs intended to be covered by this test.

paths:
  ## Interface configuration and operational state
  /interfaces/interface/config/enabled:
  /interfaces/interface/config/name:
  /interfaces/interface/state/admin-status:
  /interfaces/interface/state/enabled:
  /interfaces/interface/state/name:
  /interfaces/interface/state/oper-status:
  /interfaces/interface/state/counters/in-octets:
  /interfaces/interface/state/counters/in-pkts:
  /interfaces/interface/state/counters/out-octets:
  /interfaces/interface/state/counters/out-pkts:

  ## Routing Protocol State (BGP & IS-IS)
  /network-instances/network-instance/protocols/protocol/bgp/neighbors/neighbor/state/session-state:
  /network-instances/network-instance/protocols/protocol/isis/interfaces/interface/levels/level/adjacencies/adjacency/state/adjacency-state:

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

Required DUT platform

• FFF
• MFF