Etherchannel is the technology Cisco uses to increase bandwidth by bundling physical ports into one logical port. Ether channel has many names across the industry. Some of the names you may hear are as follows.
Those are just some of the names you may hear. Essentially all this technology does is create a logical interface for Layer 2 and 3 devices to utilize the bandwidth of all connected ports. Ether-channel also has other added benefits. Like load-balancing. You can load-balance between switches either at Layer 2 or Layer 3.
There are three different ways you can set up an Etherchannel on Cisco Catalyst switches
LACP - This is the IEEE standard EtherChannel. (This protocol negotiates.)
PAGP - Port aggregation grouping protocol. Cisco Proprietary. (This protocol negotiates.)
STATIC. (does not negotiate)
VSS
Virtual Stack Switching is a campus design implementation that logically combines the control plane of two catalyst switches to create a "single" switch.
- VSS leverages Etherchannel technologies to share Control Plane traffic between switches in a VSS stack.
VSS allows one logical control plane with dual active forwarding planes.
Uses one supervisor in each chassis with inter-chassis Stateful Switchover (SSO) method in with one supervisor is ACTIVE and the other in HOT_STANDBY mode
Active/standby supervisors run in synchronized mode (boot-env, running configuration, protocol state, and line cards status gets synchronized)
ACTIVE supervisor manages the control plane functions such as protocols (routing, EtherChannel, SNMP, telnet, etc.) and hardware control (OIR, port management)
Switchover to STANDBY_HOT supervisor occurs when ACTIVE supervisor fails to provide subsecond protocol and data forwarding recovery
