hierarchical_weight_resolution_test

TE-3.3: Hierarchical weight resolution

Summary

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

Procedure

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).

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.

Config Parameter Coverage

N/A

Telemetry Parameter Coverage

TODO: /network-instances/network-instance/afts/next-hop-groups/next-hop-group/next-hops/next-hop/state/weight

Protocol/RPC Parameter coverage

• gRIBI:
  • Modify()
    • ModifyRequest:
      • AFTOperation:
        • next_hop_group
          • NextHopGroupKey: id
          • NextHopGroup: weight

Minimum DUT platform requirement

vRX