Port Aggregation Protocol (PAgP) is a Cisco Systems proprietary networking protocol, which is used for the automated, logical aggregation of Ethernet switch ports, known as an EtherChannel. The PAgP is proprietary to Cisco Systems. A similar protocol known as LACP — released by the IEEE and known as 802.3ad or 802.1ax recently — is an industry-standard and is not tied to a specific vendor.PAgP messages are always sent to the well-known Cisco multicast address 01-00-0C-CC-CC-CC with protocol type code 0x0104. PAgP uses the same multicast group MAC address of CDP.
Link Aggregation Control Protocol or LACP is one element of an IEEE specification (802.3ad) that provides guidance on the practice of link aggregation for data connections. Importantly, LACP typically applies to strategies that bundle individual links of Ethernet connections, and not wireless transfers.