# Etherchannel

> Markdown source of <https://docs.calebsargeant.com/networking/cisco/switching/etherchannel/>.

## Two Negotiating Protocols

- Port Aggregation Protocol (PAGP)
  - Cisco Proprietary
  - Port Modes: Auto, Desirable, On
- Link Aggregatrion Control Protocol (LACP)
  - Industry standard (802.3ad)
  - Port modes: passive, active, on

## Configuring EtherChannel

### Layer 2 EtherChannel

``` text
int r g0/23 - 24
channel-protocol pagp
channel-group 1 mode desireable
show etherchannel 1 port
```

### Layer 3 EtherChannel

``` text
int r g0/23 -24
no channel-group 1
no switchport
int port-channel 1
no switchport
ip address 10.1.1.1 255.255.255.0
channel-group 1 mode desireable
```

## Best Practices

- All ports must use same speed and duplex (hard code!)
- Interfaces in a bundle are redundant
- No interfaces in bundle can be span ports
- Interfaces in a bundle must be in same VLAN / trunk
- Any changes to port-channel affects all bundled ports
- Any changes to individual ports affect only that port