SWITCH 300-115 1.2 Configure and verify Layer 2 protocols

1.2.a CDP, LLDP

https://wiki.wireshark.org/LinkLayerDiscoveryProtocol

Typically, LLDP uses Ethernet as its “transport” protocol. The Ethernet type for LLDP is 0x88cc.

LLDP Data Units (LLDPDUs) are sent to the destination MAC address 01:80:c2:00:00:0e. This address is defined as the “LLDP_Multicast” address.

There are both mandatory and optional LLDP TLVs defined. All compliant LLDP Data Units (LLDPDUs) must contain at a minimum the following four mandated TLVs in the following order :

  • Chassis ID TLV (Type = 1)
  • Port ID TLV (Type = 2)
  • Time To Live TLV (Type = 3)
  • End of LLDPDU TLV (Type = 0)

lldp_cap01

If the LLDPDU includes optional TLVs they will be inserted between the Time To Live TLV and End of LLDPDU TLV.

Optional TLVs include the Basic set of TLVS and the aptoide app download Organizationally Specific TLVS.

Besides the four mandated TLVs listed above the Basic set of LLDP TLVs also includes:

  • Port Description TLV (Type = 4)
  • System Name TLV (Type = 5)
  • System Description TLV (Type = 6)
  • System Capabilities TLV (Type = 7)
  • Management Address TLV (Type = 8)