uch as a Unix machine, use the active LACP setting. Also be aware that some devices use their own channeling methods and require the Cisco side of the EtherChannel to be set to on because they don't negotiate with the other sides of the links. CatOS example Creating an EtherChannel in CatOS is relatively straightforward once you know what you need. As an example, we'll create the EtherChannel shown in Figure 7-1. Because the devices on both sides are Cisco switches, we will configure the ports on both sides to be desirable (running PAgP and initiating negotiation): Chapter 7: Link Aggregation set port name Link #1 in Channel set port name Link #2 in Channel set port name Link #3 in Channel set port name Link #4 in Channel set vlan 20 3/1-4 set port channel 3/1-4 mode desirable Assuming the other side is set properly, this is all we need to get an EtherChannel working. The names are not necessary, of course, but everything should be labeled and documented regardless of perceived need. Protocol Description Forces the port to channel mode without negotiation. Port will passively negotiate to become an EtherChannel. Port will not initiate negotiations. desirable Port will passively negotiate to become an EtherChannel. Port will initiate negotiations. passive Port will passively negotiate to become an EtherChannel. Port will not initiate negotiations. active Port will passively negotiate to become an EtherChannel. Port will initiate negotiations. Figure 7-5. EtherChannel protocols and their modes Now that we've configured an EtherChannel, we need to be able to check on its status. First, let's look at the output of show port channel: Switch-2-Catos: (enable) sho port channel Port Status Channel Admin Ch Group Id 3/1 connected desirable 3/2 connected desirable 3/3 connected desirable 3/4 connected desirable The show channel info command shows a very similar output to show port channel, but contains even more information. In most cases, this command is far more useful, as it shows the channel ID, admin group, interface 