EtherChannel

B

The industry-standard protocol for EtherChannel is LACP, which stands for Link Aggregation Control Protocol.

LACP is a standardized protocol that is defined in IEEE 802.3ad. It allows multiple physical links between two network devices to be aggregated into a single logical link, providing higher bandwidth, redundancy, and load balancing.

LACP works by exchanging frames between the devices that want to form an EtherChannel, negotiating the terms of the channel, and verifying that the links are compatible. This negotiation process ensures that the links are configured in the same way and prevents misconfigurations that could lead to data loss or loops in the network.

PAgP, or Port Aggregation Protocol, is a Cisco proprietary protocol that performs a similar function to LACP. However, PAgP can only be used between Cisco devices and is not compatible with devices from other vendors.

Cisco Discovery Protocol (CDP) is also a Cisco proprietary protocol, but it is not used for EtherChannel configuration. Instead, CDP is used to discover and obtain information about directly connected Cisco devices.

DTP, or Dynamic Trunking Protocol, is another Cisco proprietary protocol that is used to negotiate trunk links between switches. It is not used for EtherChannel configuration.

In summary, LACP is the industry-standard protocol for EtherChannel, while PAgP is a Cisco proprietary protocol that performs a similar function. CDP and DTP are not used for EtherChannel configuration.