ospf: all router neighbors reported as neighbor on every interface

[jovatn]

Current Behavior

Tested on Infix 24.06.0 in GNS3, but bug ought to exist in 24.08.0 as well.

By reading out interface neighbors from ietf-ospf.yang, you should be able to list neighbor(s) per interface

    container neighbors {
      config false;
      description
        "All neighbors for the interface.";
      list neighbor {
        key "neighbor-router-id";
        description
          "List of interface OSPF neighbors.";
        leaf neighbor-router-id {
          type rt-types:router-id;
          description
            "Neighbor's Router ID.";
        }
        uses neighbor-state;
      }
    }

However, infix lists all neighbors of the device as neighbors on every interface (even the loopback).

Look at router "r6" in the picture below.

On its interface "eth0" it should list r4 as neighbor, which happens to have router-id 10.1.1.4, but it lists r3 (10.1.1.3) and r5 (10.1.1.5) as well. And it does so on every OSPF interface (eth0, eth1, eth2 and lo).

admin@R6:~$ sysrepocfg -X -d operational -fjson -x "/ietf-routing:routing/ietf-routing:control-plane-protocols"
{
  "ietf-routing:routing": {
    "control-plane-protocols": {
      "control-plane-protocol": [
        {
          "type": "ietf-ospf:ospfv2",
          "name": "default",
          "ietf-ospf:ospf": {
            "address-family": "ipv4",
            "router-id": "10.1.1.6",
...
            "areas": {
              "area": [
                {
                  "area-id": "0.0.0.0",
                  "area-type": "normal-area",
                  "interfaces": {
                    "interface": [
                      {
                        "name": "eth0",
                        "interface-type": "point-to-point",
                        "passive": false,
                        "enabled": true,
                        "state": "point-to-point",
                        "neighbors": {
                          "neighbor": [
                            {
                              "neighbor-router-id": "10.1.1.4",
                              "address": "10.1.1.4",
                              "dr-router-id": "0.0.0.0",
                              "bdr-router-id": "0.0.0.0",
                              "state": "full",
                              "dead-timer": 35695
                            },
                            {
                              "neighbor-router-id": "10.1.1.3",
                              "address": "10.1.1.3",
                              "dr-router-id": "0.0.0.0",
                              "bdr-router-id": "0.0.0.0",
                              "state": "full",
                              "dead-timer": 35138
                            },
                            {
                              "neighbor-router-id": "10.1.1.5",
                              "address": "10.1.1.5",
                              "dr-router-id": "0.0.0.0",
                              "bdr-router-id": "0.0.0.0",
                              "state": "full",
                              "dead-timer": 36525
                            }
                          ]
                        }
                      },
                      {
                        "name": "eth1",
                        "interface-type": "point-to-point",
  ...

Compare this with CLI status output

admin@R6:/> show ospf neighbor 

Neighbor ID     Pri State           Up Time         Dead Time Address         Interface                        RXmtL RqstL DBsmL
10.1.1.4          1 Full/-          42m49s            30.010s 10.1.1.4        eth0:10.1.1.6                        0     0     0
10.1.1.3          1 Full/-          42m50s            39.453s 10.1.1.3        eth1:10.1.1.6                        0     0     0
10.1.1.5          1 Full/-          42m49s            30.840s 10.1.1.5        eth2:10.1.1.6                        0     0     0

admin@R6:/> 

Expected Behavior

admin@R6:~$ sysrepocfg -X -d operational -fjson -x "/ietf-routing:routing/ietf-routing:control-plane-protocols"
{
  "ietf-routing:routing": {
    "control-plane-protocols": {
      "control-plane-protocol": [
        {
          "type": "ietf-ospf:ospfv2",
          "name": "default",
          "ietf-ospf:ospf": {
            "address-family": "ipv4",
            "router-id": "10.1.1.6",
...
            "areas": {
              "area": [
                {
                  "area-id": "0.0.0.0",
                  "area-type": "normal-area",
                  "interfaces": {
                    "interface": [
                      {
                        "name": "eth0",
                        "interface-type": "point-to-point",
                        "passive": false,
                        "enabled": true,
                        "state": "point-to-point",
                        "neighbors": {
                          "neighbor": [
                            {
                              "neighbor-router-id": "10.1.1.4",
                              "address": "10.1.1.4",
                              "dr-router-id": "0.0.0.0",
                              "bdr-router-id": "0.0.0.0",
                              "state": "full",
                              "dead-timer": 35695
                          }
                          ]
                        }
                      },
                      {
                        "name": "eth1",
                        "interface-type": "point-to-point",
  ...

Steps To Reproduce

1. Setup Infix 24.06.0 on (at least) three devices in GNS3 and connect them (R1 <=> R2 <=> R3)
2. Setup OSPF, preferably by point-to-point links
3. Check in CLI that they get ospf connectivity ('show ospf neighbor') on R2, and verify that R2 has a neighbor on two different interfaces.
4. Use sysrepocfg to extract yang-model of operational state on R2, sysrepocfg -X -d operational -fjson -x "/ietf-routing:routing/ietf-routing:control-plane-protocols
5. You should see that " lists R1 and R3 as neighbors on both sides.