yang(sonic-interface): name of value "Ethernet0.666" points to a non-existing leaf

[tomvil]

After enabling use-link-local-only on subinterface config override-config-table starts to generate yang error:

libyang[0]: Leafref "/sonic-port:sonic-port/sonic-port:PORT/sonic-port:PORT_LIST/sonic-port:name" of value "Ethernet0.666" points to a non-existing leaf. (path: /sonic-interface:sonic-interface/INTERFACE/INTERFACE_LIST[name='Ethernet0.666']/name)

How to reproduce:

1. Add subinterface Ethernet0.666
2. config interface ipv6 enable use-link-local-only Ethernet0.666
3. config override-config-table /etc/sonic/random_config.json
4. See the error the was mentioned above.

SONiC Software Version: SONiC.202405.0-dirty-20240916.120509
SONiC OS Version: 12
Distribution: Debian 12.7
Kernel: 6.1.0-11-2-amd64
Build commit: ee93bc7bd
Build date: Mon Sep 16 09:11:13 UTC 2024
Built by: netop@netop

[wen587]

Hi @tomvil , did you try use config to check what the config should be?
I tried locally with config like below:

sudo config subinterface add Ethernet4.10
sudo config interface ip add Ethernet4.10 172.16.2.1/24

After that, the config looks like below:

{
...
    "VLAN_SUB_INTERFACE": {
        "Ethernet4.10": {
            "admin_status": "up"
        },
        "Ethernet4.10|172.16.2.1/24": {}
    },
...
}

It will not cause INTERFACE leafref issue since Ethernet4.10 is not located in INTERFACE table.

[tomvil]

hey @wen587 , the command that is causing subinterface creation in INTERFACE section is config interface ipv6 enable use-link-local-only Ethernet0.666. We want to use bgp unnumbered with subinterface and it's working fine after enabling use-link-local-only, but we start to see this error.

# show runningconfiguration all | jq .INTERFACE
{
  "Ethernet0.666": {
    "ipv6_use_link_local_only": "enable"
  }
}

[wen587]

So the config would be:

{
    "INTERFACE": {
        "Ethernet0.666": {
            "ipv6_use_link_local_only": "enable"
        }
    },
    "VLAN_SUB_INTERFACE": {
        "Ethernet0.666": {
            "admin_status": "up"
        }
    },
}

YANG model failed to recognize this Ethernet0.666 in INTERFACE table.
It could be the yang support missing in this case when add this use-link-local-only in #14757

[tomvil]

@wen587 I think it would be the best to keep the "ipv6_use_link_local_only": "enable" config in VLAN_SUB_INTERFACE for subinterfaces.

For VLAN interface it's done like:

    "VLAN_INTERFACE": {
        "Vlan1000": {
            "ipv6_use_link_local_only": "enable"
        }
    }

I think it should be the same for VLAN_SUB_INTERFACE as well, something like:

{
    "VLAN_SUB_INTERFACE": {
        "Ethernet0.666": {
            "admin_status": "up",
            "ipv6_use_link_local_only": "enable"
        }
    }
}

[wen587]

Hi @AkhileshSamineni , could you check this? I think it is a miss that not consider the sub interface case.

@wen587 I think it would be the best to keep the "ipv6_use_link_local_only": "enable" config in VLAN_SUB_INTERFACE for subinterfaces.

For VLAN interface it's done like:

    "VLAN_INTERFACE": {
        "Vlan1000": {
            "ipv6_use_link_local_only": "enable"
        }
    }

I think it should be the same for VLAN_SUB_INTERFACE as well, something like:

{
    "VLAN_SUB_INTERFACE": {
        "Ethernet0.666": {
            "admin_status": "up",
            "ipv6_use_link_local_only": "enable"
        }
    }
}

[tomvil]

@wen587 @AkhileshSamineni any updates on this?