What is the difference between EtherChannel auto and desirable modes?

Auto mode: it passively negotiates PAgP aggregation. If the remote end of the link is also configured with Auto mode, a PAgP EtherChannel will not form. Auto side is waiting for negotiation to start from the other end. Desirable mode:that actively negotiates PAgP.

What is channel group mode desirable?

desirable means try and negotiate with the other side, and if he agrees, then enable the channel. If you have on on one side and desirable on the other, then it will not form a channel because no negotiation will take place.

Should I use PAgP or LACP?

Both LACP and PAGP protocols are used for link aggregation. Besides, LACP can support cross-stack, while PAGP does not since it does not support participating interfaces on different physical switches. Thus if you need to form the Etherchannel on stack switch, it is better to choose LACP instead of PAGP.

What is an advantage of using on on mode for EtherChannel *?

Etherchannel is a link aggregation technology used primarily on Cisco switches. EtherChannel enables bundling of multiple physical Ethernet links to create one logical Ethernet link which provides high throughout and resilient links. EtherChannel can be provisioned across Cisco Switches and Routers.

What is mode desirable?

switchport mode dynamic desirable: Makes the interface actively attempt to convert the link to a trunk link. The interface becomes a trunk interface if the neighboring interface is set to trunk, desirable, or auto mode.

What is the difference between LACP and EtherChannel?

EtherChannel vs. Both technologies are capable of automatically configuring this logical link. EtherChannel supports both LACP and Cisco’s PAgP, whereas 802.3ad uses LACP. LACP allows for up to 8 active and 8 standby links, whereas PAgP only allows for 8 active links.

When would you use LACP?

Another useful feature of LACP is that when one member link stops sending LACPDUs (if the cable is unplugged, for example), it is removed from the LAG. This helps to minimize packet loss. Both devices must support LACP for you to set up a dynamic LAG between those devices.

Does LACP load balance?

LACP Load Balance Algorithm Standard mode of load balancing packets across LACP EtherChannel if per flow so each flow will always get one of the bundled links to get to the other side. On some switches, you can even change the load balancing so that it works per packet and not per flow, but that is not best practice.

What is the process to configure EtherChannel?

The basic process for configuring your EtherChannel interfaces is as follows: Connect to the command-line interface (CLI) your switch. Access Privileged EXEC mode. Access Global Configuration mode. Access Interface Configuration mode. Change switchport to trunk or access, but all ports must be in the same VLAN.

Does EtherChannel require LACP or PAgP?

Do not configure an EtherChannel in both the PAgP and LACP modes. EtherChannel groups running PAgP and LACP can coexist on the same switch or on different switches in the stack. Individual EtherChannel groups can run either PAgP or LACP , but they cannot interoperate.

What are Cisco port channels?

This port channel uses Link Aggregation and Control Protocol (LACP) or in the Cisco world, could also use Port Aggregation Protocol (PAgP) to signal the establishment of the channel between two devices. A port channel does a couple of things: Increases the available bandwidth between two devices.

What are port channels?

Port channels. A port channel bundles individual links into a single logical link that provides redundancy and aggregate bandwidth of up to eight physical links.