Ensures that next-hop weights (for WCMP) are honored hierarchically in gRIBI recursive resolution and traffic is load-shared according to these weights.

Configure ATE and DUT:

• Connect ATE port-1 to DUT port-1. ATE port-2 to DUT port-2.

• Create a non-default VRF (VRF-1) that contains no interfaces.

• On DUT port-2 and ATE port-2 create 18 L3 sub-interfaces each with a /30 subnet as below:

  • On DUT port-2, create subinterfaces with indices 1 to 18 mapped to VLAN IDs 1 to 18 and corressponding IPv4 addresses 192.0.2.5, 192.0.2.9, ..., 192.0.2.73 respectively.

  • On ATE port-2, create subinterfaces with indices 1 to 18 mapped to VLAN IDs 1 to 18 and corresponding IPv4 addresses 192.0.2.6, 192.0.2.10, ..., 192.0.2.74 and default gateways as 192.0.2.5, 192.0.2.9, ..., 192.0.2.73 respectively.

• On DUT port-1 and ATE port-1 create a single L3 interface.

• On DUT, create a policy-based forwarding rule to redirect all traffic received from DUT port-1 into VRF-1 (based on src. IP match criteria).

• Add an empty decap VRF, DECAP_TE_VRF.

• Add 4 empty encap VRFs, ENCAP_TE_VRF_A, ENCAP_TE_VRF_B, ENCAP_TE_VRF_C and ENCAP_TE_VRF_D.

• Replace the existing VRF selection policy with vrf_selection_policy_w as in https://github.com/openconfig/featureprofiles/pull/2217

Test case for basic hierarchical weight:

• Establish gRIBI client connection with DUT with PERSISTENCE, make it become leader and install the following Entries:

  • IPv4Entry 203.0.113.0/32 in VRF-1, pointing to NextHopGroup(NHG#1) in default VRF, with two NextHops(NH#1, NH#2) in default VRF:

    • NH#1 with weight:1, pointing to 192.0.2.111

    • NH#2 with weight:3, pointing to 192.0.2.222

  • IPv4Entry 192.0.2.111/32 in default VRF, pointing to NextHopGroup(NHG#2) in default VRF, with two NextHops(NH#10, NH#11) in default VRF:

    • NH#10 with weight:1, pointing to 192.0.2.10

    • NH#11 with weight:3, pointing to 192.0.2.14

  • IPv4Entry 192.0.2.222/32 in default VRF, pointing to NextHopGroup(NHG#3) in default VRF, with two NextHops(NH#100, NH#101) in default VRF:

    • NH#100 with weight:3, pointing to 192.0.2.18

    • NH#101 with weight:5, pointing to 192.0.2.22

• Validate with traffic:

  • NH10: (1/4) * (1/4) = 6.25% traffic received by ATE port-2 VLAN 1

  • NH11: (1/4) * (3/4) = 18.75% traffic received by ATE port-2 VLAN 2

  • NH100: (3/4) * (3/8) = 28.12% traffic received by ATE port-2 VLAN 3

  • NH101: (3/4) * (5/8) = 46.87% traffic received by ATE port-2 VLAN 4

  • A tolerance of 0.2% is allowed for each VLAN for now, since we only test for 2 mins.

Test case for hierarchical weight in boundary scenarios, with maximum expected WCMP width of 16 nexthops:

• Flush previous gRIBI Entries for all NIs and establish a new connection with DUT with PERSISTENCE and install the following Entries:

  • IPv4Entry 203.0.113.0/32 in VRF-1, pointing to NextHopGroup(NHG#1) in default VRF, with two NextHops(NH#1, NH#2) in default VRF:

    • NH#1 with weight:1, pointing to 192.0.2.111

    • NH#2 with weight:31, pointing to 192.0.2.222

  • IPv4Entry 192.0.2.111/32 in default VRF, pointing to NextHopGroup(NHG#2) in default VRF, with two NextHops(NH#10, NH#11) in default VRF:

    • NH#10 with weight:3, pointing to 192.0.2.10

    • NH#11 with weight:5, pointing to 192.0.2.14

  • IPv4Entry 192.0.2.222/32 in default VRF, pointing to NextHopGroup(NHG#3) in default VRF, with 16 NextHops(NH#100, NH#101, ..., NH#115), all with weight: 16 except NHG#100 is of weight 1, in default VRF:

    • NH#100 with weight:1, pointing to 192.0.2.18

    • NH#101 with weight:16, pointing to 192.0.2.22

    • ...

    • NH#115 with weight:16, pointing to 192.0.2.79

• Validate with traffic:

  • NH10: (1/32) * (3/8) ~ 1.171% traffic received by ATE port-2 VLAN 1

  • NH11: (1/32) * (5/8) ~ 1.953% traffic received by ATE port-2 VLAN 2

  • NH100: (31/32) * (1/241) ~ 0.402% traffic received by ATE port-2 VLAN 3

  • for each VLAN ID in 4...18:

    • NH: (31/32) * (16/241) ~ 6.432% traffic received by ATE port-2 VLAN ID

  • A tolerance of 0.2% is allowed for each VLAN for now, since we only test for 2 mins.

rpcs:
  gnmi:
    gNMI.Get:
    gNMI.Set:
    gNMI.Subscribe:
  gribi:
    gRIBI.Get:
    gRIBI.Modify:
    gRIBI.Flush:

vRX