Hi @Ethan-TP could you please check your information about the LLDP discarded packet count? Investigating, I find that LLDP information is only received by switch ports when the LLDP packets are _not_ discarded. The LLDP packets sent from ER7412-M2 are the only ones being discarded by the switch, and the switch has no LLDP information for that port.

The only port on any switch showing Discard-Pkt count is for LLDP packets are for those sent from the ER7412-M2 gateway to the SG2210XMP-M2 switch:

On that port there is no LLDP information available, since it seems the switch is discard the LLDP packets from the ER7412-M2 gateway as invalid.

Below is a capture of one of the LLDP packets sent by the ER7412-M2 gateway, that is being rejected and discarded by the SG2210XMP-M2 switch.

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Packet comments
    LLDP from ER7412-M2 gateway to the SG2210XMP-M2 switch, these packets are discarded by the switch as invalid
Frame 23708: 213 bytes on wire (1704 bits), 213 bytes captured (1704 bits) on interface enx6c1ff7615794, id 0
Ethernet II, Src: aa:bb:cc:dd:ee:ff (aa:bb:cc:dd:ee:ff), Dst: LLDP_Multicast (01:80:c2:00:00:0e)
    Destination: LLDP_Multicast (01:80:c2:00:00:0e)
    Source: aa:bb:cc:dd:ee:ff (aa:bb:cc:dd:ee:ff)
    Type: 802.1 Link Layer Discovery Protocol (LLDP) (0x88cc)
    Trailer: 320000
Link Layer Discovery Protocol
    Chassis Subtype = MAC address, Id: aa:bb:cc:dd:ee:ff
        0000 001. .... .... = TLV Type: Chassis Id (1)
        .... ...0 0000 0111 = TLV Length: 7
        Chassis Id Subtype: MAC address (4)
        Chassis Id: aa:bb:cc:dd:ee:ff (aa:bb:cc:dd:ee:ff)
    Port Subtype = MAC address, Id: aa:bb:cc:dd:ee:ff
        0000 010. .... .... = TLV Type: Port Id (2)
        .... ...0 0000 0111 = TLV Length: 7
        Port Id Subtype: MAC address (3)
        Port Id: aa:bb:cc:dd:ee:ff (aa:bb:cc:dd:ee:ff)
    Time To Live = 120 sec
        0000 011. .... .... = TLV Type: Time to Live (3)
        .... ...0 0000 0010 = TLV Length: 2
        Seconds: 120
    System Name = Internet Gateway
        0000 101. .... .... = TLV Type: System Name (5)
        .... ...0 0001 0000 = TLV Length: 16
        System Name: Internet Gateway
    System Description = Omada Multi-Gigabit VPN Gateway
        0000 110. .... .... = TLV Type: System Description (6)
        .... ...0 0001 1111 = TLV Length: 31
        System Description: Omada Multi-Gigabit VPN Gateway
    Capabilities
        0000 111. .... .... = TLV Type: System Capabilities (7)
        .... ...0 0000 0100 = TLV Length: 4
        Capabilities: 0x0014
            .... .... .... ...0 = Other: Not capable
            .... .... .... ..0. = Repeater: Not capable
            .... .... .... .1.. = Bridge: Capable
            .... .... .... 0... = WLAN access point: Not capable
            .... .... ...1 .... = Router: Capable
            .... .... ..0. .... = Telephone: Not capable
            .... .... .0.. .... = DOCSIS cable device: Not capable
            .... .... 0... .... = Station only: Not capable
            .... ...0 .... .... = C-VLAN component: Not capable
            .... ..0. .... .... = S-VLAN component: Not capable
            .... .0.. .... .... = TPMR component: Not capable
            .... ...0 .... .... = C-VLAN component: Not capable
            .... ..0. .... .... = S-VLAN component: Not capable
            .... .0.. .... .... = TPMR component: Not capable
        Enabled Capabilities: 0x0014
            .... .... .... ...0 = Other: Not capable
            .... .... .... ..0. = Repeater: Not capable
            .... .... .... .1.. = Bridge: Capable
            .... .... .... 0... = WLAN access point: Not capable
            .... .... ...1 .... = Router: Capable
            .... .... ..0. .... = Telephone: Not capable
            .... .... .0.. .... = DOCSIS cable device: Not capable
            .... .... 0... .... = Station only: Not capable
    Management Address
        0001 000. .... .... = TLV Type: Management Address (8)
        .... ...0 0000 1100 = TLV Length: 12
        Address String Length: 5
        Address Subtype: IPv4 (1)
        Management Address: 192.168.0.1
        Interface Subtype: Unknown (1)
        Interface Number: 0
        OID String Length: 0
    Port Description = inf.1
        0000 100. .... .... = TLV Type: Port Description (4)
        .... ...0 0000 0101 = TLV Length: 5
        Port Description: inf.1
    IEEE 802.1 Chair - VLAN Name
        1111 111. .... .... = TLV Type: Organization Specific (127)
        .... ...0 0000 1100 = TLV Length: 12
        Organization Unique Code: 00:80:c2 (IEEE 802.1 Chair)
        IEEE 802.1 Subtype: VLAN Name (0x03)
        VLAN Identifier: 1 (0x0001)
        VLAN Name Length: 5
        VLAN Name: inf.1
    Telecommunications Industry Association TR-41 Committee - Media Capabilities
        1111 111. .... .... = TLV Type: Organization Specific (127)
        .... ...0 0000 0111 = TLV Length: 7
        Organization Unique Code: 00:12:bb (Telecommunications In
        Media Subtype: Media Capabilities (0x01)
        Capabilities: 0x0021
            .... .... .... ...1 = LLDP-MED Capabilities: Capable
            .... .... .... ..0. = Network Policy: Not capable
            .... .... .... .0.. = Location Identification: Not capable
            .... .... .... 0... = Extended Power via MDI-PSE: Not capable
            .... .... ...0 .... = Extended Power via MDI-PD: Not capable
            .... .... ..1. .... = Inventory: Capable
        Class Type: Network Connectivity (4)
    Telecommunications Industry Association TR-41 Committee - Inventory - Hardware Revision
        1111 111. .... .... = TLV Type: Organization Specific (127)
        .... ...0 0000 1000 = TLV Length: 8
        Organization Unique Code: 00:12:bb (Telecommunications In
        Media Subtype: Inventory - Hardware Revision (0x05)
        Hardware Revision: 1.20
    Telecommunications Industry Association TR-41 Committee - Inventory - Software Revision
        1111 111. .... .... = TLV Type: Organization Specific (127)
        .... ...0 0010 0010 = TLV Length: 34
        Organization Unique Code: 00:12:bb (Telecommunications In
        Media Subtype: Inventory - Software Revision (0x07)
        Software Revision: 1.1.0 Build 20251015 Rel.aa:bb:cc:dd:ee:ff
    Telecommunications Industry Association TR-41 Committee - Inventory - Manufacturer Name
        1111 111. .... .... = TLV Type: Organization Specific (127)
        .... ...0 0000 1011 = TLV Length: 11
        Organization Unique Code: 00:12:bb (Telecommunications In
        Media Subtype: Inventory - Manufacturer Name (0x09)
        Manufacturer Name: TP-Link
    Telecommunications Industry Association TR-41 Committee - Inventory - Model Name
        1111 111. .... .... = TLV Type: Organization Specific (127)
        .... ...0 0000 1101 = TLV Length: 13
        Organization Unique Code: 00:12:bb (Telecommunications In
        Media Subtype: Inventory - Model Name (0x0a)
        Model Name: ER7412-M2
    End of LLDPDU
        0000 000. .... .... = TLV Type: End of LLDPDU (0)
        .... ...0 0000 0000 = TLV Length: 0

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Capturing other packets between switches I notice the gateway includes TR-41 nodes, that other LLDP packets do not. Could it be that Omada switches can't handle those nodes?

From Switch:

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Frame 11688: 230 bytes on wire (1840 bits), 230 bytes captured (1840 bits) on interface enp0s31f6, id 0
Ethernet II, Src: TpLinkPte_a3:05:1d (aa:bb:cc:dd:ee:ff), Dst: LLDP_Multicast (01:80:c2:00:00:0e)
Link Layer Discovery Protocol
    Chassis Subtype = MAC address, Id: aa:bb:cc:dd:ee:ff
    Port Subtype = Interface name, Id: gigabitEthernet 1/0/21
    Time To Live = 120 sec
    System Name = Main Switch
    System Description = Omada 28-Port Gigabit Smart Switch with 16-Port PoE+
    Capabilities
    Management Address
    Port Description = Port21
    IEEE 802.1 Chair - Port VLAN ID
    IEEE 802.1 Chair - Port and Protocol VLAN ID
    IEEE 802.1 Chair - VLAN Name
    Ieee 802.3 - Link Aggregation
    Ieee 802.3 - MAC/PHY Configuration/Status
    Ieee 802.3 - Power Via MDI
    Ieee 802.3 - Maximum Frame Size
    End of LLDPDU
----------------------------

From Gateway:

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Frame 12334: 213 bytes on wire (1704 bits), 213 bytes captured (1704 bits) on interface enx6c1ff7615794, id 1
Ethernet II, Src: aa:bb:cc:dd:ee:ff (aa:bb:cc:dd:ee:ff), Dst: LLDP_Multicast (01:80:c2:00:00:0e)
Link Layer Discovery Protocol
    Chassis Subtype = MAC address, Id: aa:bb:cc:dd:ee:ff
    Port Subtype = MAC address, Id: aa:bb:cc:dd:ee:ff
    Time To Live = 120 sec
    System Name = Internet Gateway
    System Description = Omada Multi-Gigabit VPN Gateway
    Capabilities
    Management Address
    Port Description = inf.1
    IEEE 802.1 Chair - VLAN Name
    Telecommunications Industry Association TR-41 Committee - Media Capabilities
    Telecommunications Industry Association TR-41 Committee - Inventory - Hardware Revision
    Telecommunications Industry Association TR-41 Committee - Inventory - Software Revision
    Telecommunications Industry Association TR-41 Committee - Inventory - Manufacturer Name
    Telecommunications Industry Association TR-41 Committee - Inventory - Model Name
    End of LLDPDU
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