Overview:
Link Layer Discovery Protocol LLDP is similar to CDP in that it supports non-Cisco devices
Study Notes:
Link Layer Discovery Protocol (LLDP):
- Link Layer Discovery Protocol (LLDP) is a device discovery protocol that runs over Layer 2 (the data link layer) on many devices (routers, bridges, access servers, and switches)
- LLDP allows network management applications to automatically discover and learn about other LLDP enabled devices on the network
- IEEE 802.1AB LLDP protocol is used to allow for interoperability between non-Cisco devices
- LLDP is a neighbor discovery protocol that is used for network devices to advertise information about themselves to other devices on the network
- This protocol runs over the data-link layer, which allows two systems running different network layer protocols to learn about each other.
- LLDP supports a set of attributes that it uses to discover neighbor devices
- These attributes contain type, length, and value descriptions and are referred to as TLVs
- LLDP supported devices can use TLVs to receive and send information to their neighbors
- Details such as configuration information, device capabilities, and device identity can be advertised using this protocol
- The switch supports the following basic management TLVs, which are optional:
- Port description TLV
- System name TLV
- System description TLV
- System capabilities TLV
- Management address TLV
- These organizationally specific LLDP TLVs are also advertised to support LLDP-MED
- Port VLAN ID TLV ((IEEE 802.1 organizationally specific TLVs)
- MAC/PHY configuration/status TLV(IEEE 802.3 organizationally specific TLVs)
- Optional LLDP settings include
- holdtime - amount of time receiving device holds my info before discarding (default 120)
- reinit - delay time in seconds for LLDP to initialize on any interface (default 2)
- timer - transmission frequency of LLDP updates in seconds (default 30)
- tlv-select - specifies the LLDP TLVs to send or receive
- med-tlv-select - specifies the LLDP-MED TLVs to send or receive
PacketTracer Lab: CCNA-2.8.b-How-to-configure-Link-Layer-Discovery-Protocol-LLDP.pkt
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