Add leaves for common org-defined TLVs to LLDP neighbor state

[yogeshg-arista]

Resolves Issue #1471

• (M) release/models/lldp/openconfig-lldp.yang

Change Scope

• Add the following new read-only leaves under /lldp/interfaces/interface/neighbors/neighbor/state for widely implemented, standards-based LLDP TLVs:

  • med-inventory-serial-number (string) — LLDP-MED Inventory Serial Number TLV (OUI 00-12-BB, subtype 8)
  • port-vlan-id (uint16 { range 0..4094 }) — IEEE 802.1 Port VLAN ID TLV (OUI 00-80-C2, subtype 1)
  • link-aggregation (container) — IEEE 802.3 Link Aggregation TLV (OUI 00-12-0F, subtype 3), containing:
  • • capable (boolean)
  • • enabled (boolean)
  • • port-id (uint32)
  • max-frame-size (uint16) — IEEE 802.3 Maximum Frame Size (OUI 00-12-0F, subtype 4)

• These TLVs are defined in IEEE 802.1, IEEE 802.3, and ANSI/TIA-1057 and are broadly supported across network platforms. They are essential for network automation use cases including inventory management.

• This change is backward compatible (minor version bump 1.1.0 → 1.2.0).

Platform Implementations

• Arista: These TLVs are supported in EOS CLI via show lldp neighbors detail. See LLDP EOS User Manual and sample CLI output below.

  Interface Ethernet36/1 detected 1 LLDP neighbors:
  
    Neighbor 3838.a6a5.5d04/"Ethernet36/1", age 7 seconds
    - IEEE802.1 Port VLAN ID: 0
    - IEEE802.3 Link Aggregation
      Link Aggregation Status: Capable, Enabled (0x03)
      Port ID                : 1000002
    - IEEE802.3 Maximum Frame Size: 10240 bytes
    - LLDP-MED Inventory Serial Number TLV: "FGN234408B7"
  

Tree View

 module: openconfig-lldp 
 path: /lldp/interfaces/interface/neighbors/neighbor/state
   +--ro state
      +--ro system-name?                   string
      +--ro system-description?            string
      +--ro chassis-id?                    string
      +--ro chassis-id-type?               oc-lldp-types:chassis-id-type
      +--ro management-interface?          oc-if:interface-id
      +--ro id?                            string
      +--ro age?                           uint64
      +--ro last-update?                   int64
      +--ro ttl?                           uint16
      +--ro port-id?                       string
      +--ro port-id-type?                  oc-lldp-types:port-id-type
      +--ro port-description?              string
      x--ro management-address?            string
      x--ro management-address-type?       string
+     +--ro med-inventory-serial-number?   string
+     +--ro port-vlan-id?                  uint16
+     +--ro link-aggregation-capable?      boolean
+     +--ro link-aggregation-enabled?      boolean
+     +--ro link-aggregation-port-id?      uint32
+     +--ro max-frame-size?                uint16
+     +--ro med-inventory-serial-number?   string
+     +--ro port-vlan-id?                  uint16
+     +--ro link-aggregation
+     |  +--ro capable?   boolean
+     |  +--ro enabled?   boolean
+     |  +--ro port-id?   uint32
+     +--ro max-frame-size?                uint16

[gemini-code-assist]

Code Review

This pull request updates the LLDP model to version 1.1.0, introducing new neighbor state leaves for LLDP-MED inventory serial numbers, IEEE 802.1 port VLAN IDs, and IEEE 802.3 link aggregation and maximum frame size. The review feedback highlights that the port-vlan-id should be adjusted to allow a value of 0 for non-VLAN-aware ports and suggests replacing the uint8 bitfield for link aggregation with explicit boolean leaves to follow OpenConfig conventions for telemetry usability.

[dplore]

/gcbrun

[OpenConfigBot]

No major YANG version changes in commit cdbef70

[rgwilton]

Re:

+     +--ro med-inventory-serial-number?   string
+     +--ro port-vlan-id?                  uint16
+     +--ro link-aggregation-capable?      boolean
+     +--ro link-aggregation-enabled?      boolean
+     +--ro link-aggregation-port-id?      uint32
+     +--ro max-frame-size?                uint16

I would suggest putting the three link-aggregation fields into a link-aggregation container, and then naming the fields capable, enabled, port-id.

[ElodinLaarz]

Reviewed at the OC Community Meeting May 7th, 2026:

Could we get another vendor to review / comment if they already implement this behavior?

[ElodinLaarz]

/gcbrun

[yogeshg-arista]

Re:

+     +--ro med-inventory-serial-number?   string
+     +--ro port-vlan-id?                  uint16
+     +--ro link-aggregation-capable?      boolean
+     +--ro link-aggregation-enabled?      boolean
+     +--ro link-aggregation-port-id?      uint32
+     +--ro max-frame-size?                uint16

I would suggest putting the three link-aggregation fields into a link-aggregation container, and then naming the fields capable, enabled, port-id.

I have created the container link-aggregation with leaves capable, enabled and port-id.