This is to test the functionality of decapsulation of static GUEv1 to IPv4 or IPv6 payload (GUE Variant 1). These tests verify the use case of IPv4 and IPv6 encapsulated traffic in IPv4 GUE tunnel.

The tests validate that the DUT performs the following action-

• Decapsulate the outer (UDPoIPv4) headers of GUE packets destined to the locally configured decap IPv4 over DECAP subnet range and matching UDP port.
• Decapsulate the packet only if it matches the locally configured decap IPv4 address/addresses and matching UDP port port/port-range.
• Post decapsulation the DUT should
  • Maintain the inner TTL (do not copy outer TTL to the inner TTL)
  • Maintain the inner DSCP (do not copy outer DSCP to inner DSCP)
• Post decapsulation, the inner TTL value will be decremented before egressing to next-hop
• Traffic not subject to match criteria will be forwared using the traditional IP forwarding.

Comprehensive GUEv1 decapsulation and ECMP hashing test for GUE flows with IPv4|UDP outer header on decapsulation node is documented in PF-1.22

• Create the following connections:
• DUT has ingress and egress port connected to the ATE.

graph LR; 
A[ATE:Port1] --Ingress--> B[Port1:DUT:Port2];B --Egress--> C[Port2:ATE];

• ATE Port 1: Generates GUE-encapsulated traffic

• ATE Port 2: Receives traffic

• ATE Port 1 hosted prefixes:

  • ATE-Port1 IPV4 address = ATE-P1-Address
  • Additional Source Address advertised
    • IPV4-SRC1
    • IPV6-SRC1

• ATE Port 2 hosted prefixes:

  • ATE-Port2 IPV4 address = ATE-P2-Address
  • Additional destination address advertised
    • IPV4-DST1
    • IPV6-DST1

• ATE Port 1 generates below flow types:

• ATE Port 2 receives below flow/packet types:

1. Interfaces: Configure all DUT ports as singleton IP interfaces towards the ATE ports

2. GUE Decapsulation:

   • Configure a Loopback address with DECAP-DST_3/32 address
   • Configure static routes for destination IPV4-SRC1 and IPV6-SRC1 towards ATE Port 1
   • Configure static routes for destination IPV4-DST1 and IPV6-DST1 towards ATE Port 2
   • Configure the DUT as GUEv1 decapsulator with below fields:
     • DECAP-DST-SUBNET/30 as decapsulation subnet-range
       • DECAP-DST/32 is one of the IP prefix from DECAP-DST-SUBNET/30
     • Do not enable copying TTL bits from outer to inner header post decapsulation
     • Use single decapsulation UDP destination port 6081 for both IPv4 and IPv6 payload type
   • Configure IXIA with a static route for DECAP-DST-SUBNET/30 towards the DUT<>ATE Port 1

• DECAP-DST-SUBNET/30 subnet comprises of below IP prefixes:

  • DECAP-DST_1/32
  • DECAP-DST_2/32
  • DECAP-DST_3/32
  • DECAP-DST_4/32

• DUT hosted IPv4 prefixes:

  • Loopback Address = DECAP-DST_3/32

Traffic:

• Generate the applicable GUE-encapsulated flow from ATE Port 1
  • Send 1000 packets at the 10% of the line rate.
  • Keep the frame size Internet Mix.
    • Do not include the 16,000 MTU frame size in the testing, as DUT is not enabled to support it.

• Push DUT configuration
• Initiate traffic flow type#1
• Verification:
  • The outer header destination IP of the traffic falls within the configured decap range (DECAP-DST-SUBNET/30)
  • The outer header destination port of the traffic (UDP 6081) matches the configured decap port criteria
  • The DUT will decapsulate the outer header and perform the lookup based on the inner IP address
  • The TTL bits will not be copied to the inner header
  • The inner header TTL value will be decremented by 1
  • The inner packet's DSCP value (32) will be preserved
  • The DUT will forward the traffic towards ATE Port 2
  • The relevant DUT counters will reflect 1000 decapsulated packets
  • ATE Port 2 receives 1000 packets structured as RX-Flow-type#2
  • No packet loss should be observed

• Push DUT configuration.
• Initiate traffic flow type#2
• Verification:
  • The outer header destination IP of the traffic falls within the configured decap range (DECAP-DST-SUBNET/30)
  • The outer header destination port of the traffic (UDP 6081) matches the configured decap port criteria
  • The DUT will decapsulate the outer header and perform the lookup based on the inner IP address
  • The TTL bits will not be copied to the inner header
  • The inner header TTL value will be decremented by 1
  • The inner packet's DSCP value (32) will be preserved
  • The DUT will forward the traffic towards ATE Port 2
  • The relevant DUT counters will reflect 1000 decapsulated packets
  • ATE Port 2 receives 1000 packets structured as RX-Flow-type#4
  • No packet loss should be observed

• Push DUT configuration.
• Initiate traffic flow type#3
• Verification:
  • The outer header destination IP of the traffic falls within the DECAP-DST-SUBNET/30 range
  • The outer header destination UDP port (6085) of the traffic is not configured for decapsulation, therefore it does not match the decapsulation criteria.
  • The DUT should not decapsulate these packets. Packets with DECAP-DST_3/32 will be sent to the device controller/CPU while the packets with DECAP-DST_1/32, DECAP-DST_2/32 and DECAP-DST_4/32 will be dropped due to specific no-route to the destination present in local FIB
  • The DUT decapsulation counters should not increment for this flow
  • 100% packet loss should be observed on ATE Port 2

• Push DUT configuration.
• Initiate traffic flow type#4
• Verification:
  • The outer header destination IP of the traffic falls within the DECAP-DST-SUBNET/30 range
  • The outer header destination UDP port (6085) of the traffic is not configured for decapsulation, therefore it does not match the decapsulation criteria.
  • The DUT should not decapsulate these packets. Packets should be dropped since no specific drop rule exists for unmatched GUE
  • The DUT decapsulation counters should not increment for this flow
  • The DUT drop counters will reflect the packets to 1000
  • 100% packet loss should be observed on ATE Port 2

• Push DUT configuration.
• Initiate traffic flow type#5
• Verification:
  • The outer header destination UDP port (6081) matches a configured decap port
  • The outer header destination IP (ATE-P2-Address) of the traffic does not fall within the configured decap range (DECAP-DST-SUBNET/30), therefore it does not match the decapsulation criteria for the destination IP
  • The DUT will not decapsulate the outer header. Instead, it will perform a lookup based on the outer destination IP address and forward the packets as standard IP traffic
  • ATE Port 2 receives 1000 packets structured as RX-Flow-type#7 (original GUE encapsulated packets, outer TTL decremented by DUT)
  • No packet loss should be observed for this flow

• Push DUT configuration.
• Initiate traffic flow type#6
  • Verification:
  • The outer header destination UDP port (6081) matches a configured decap port
  • The outer header destination IP (ATE-P2-Address) of the traffic does not fall within the configured decap range (DECAP-DST-SUBNET/30), therefore it does not match the decapsulation criteria for the destination IP
  • The DUT will not decapsulate the outer header. Instead, it will perform a lookup based on the outer destination IP address and forward the packets as standard IP traffic
  • ATE Port 2 receives 1000 packets structured as RX-Flow-type#8 (original GUE encapsulated packets, outer TTL decremented by DUT)
  • No packet loss should be observed

TODO: decap policy to be updated by https://github.com/openconfig/public/pull/1288

{
    "network-instances": {
        "network-instance": {
            "config": {
                "name": "DEFAULT"
            },
            "name": "DEFAULT",
            "policy-forwarding": {
                "policies": {
                    "policy": [
                        {
                            "config": {
                                "policy-id": "decap-policy"
                            },
                            "rules": {
                                "rule": [
                                    {
                                        "sequence-id": 1,
                                        "config": {
                                            "sequence-id": 1
                                        },
                                        "ipv4": {
                                            "config": {
                                                "destination-address-prefix-set": "dst_prefix",
                                                "protocol": "IP_UDP"
                                            }
                                        },
                                        "transport": {
                                            "config": {
                                                "destination-port": 6080
                                            }
                                        }
                                        "action": {
                                            "decapsulate-gue": true
                                        },
                                    },
                                ]
                            }
                        }
                    ]
                }
            }
        }
    }
}

# paths:

/network-instances/network-instance/policy-forwarding/policies/policy/config/policy-id:
/network-instances/network-instance/policy-forwarding/policies/policy/rules/rule/config/ipv4/config/destination-address-prefix-set:
/network-instances/network-instance/policy-forwarding/policies/policy/rules/rule/config/ipv4/config/protocol:
/network-instances/network-instance/policy-forwarding/policies/policy/rules/rule/transport/config/destination-port:
/network-instances/network-instance/policy-forwarding/policies/policy/rules/rule/action/decapsulate-gue:

# telemetry
openconfig-interfaces/interfaces/interface/state/counters/out-pkts:
openconfig-interfaces/interfaces/interface/state/counters/out-unicast-pkts:
openconfig-network-instance/network-instances/network-instance/policy-forwarding/policies/policy/rules/rule/state/matched-pkts:
openconfig-network-instance/network-instances/network-instance/policy-forwarding/policies/policy/rules/rule/state/matched-octets:

rpcs:
  gnmi:
    gNMI.Set:
      union_replace: true
      replace: true
    gNMI.Subscribe:
      on_change: true

• Specify the minimum DUT-type:
  • FFF - fixed form factor