> For the complete documentation index, see [llms.txt](https://mudassirs46.gitbook.io/network-fundamentals/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mudassirs46.gitbook.io/network-fundamentals/ether-channel.md). # Ether Channel If we paid hefty amount for each individual links between the 2 Switches & all of those links are in Discarding Mode & only 1 is used due to [STP](https://app.gitbook.com/@mudassirs46/s/network-fundamentals/~/drafts/-MRZ8l67L5MHnaQIEh9W/stp-spanning-tree-protocol)/[RSTP ](https://app.gitbook.com/@mudassirs46/s/network-fundamentals/~/drafts/-MRZ8l67L5MHnaQIEh9W/rstp-rapid-spanning-tree)then we need a port bundling mechanism to group those ports as 1 single port. * Ether Channel is the solution to bundle multiple ports/links as a single logical link. * Ether Channel is the logical aggregation of similar links. * Ether Channel does Load Balancing between those links. * Ether Channel provides Redundancy for up to 16 links. * Ether Channel works only on directly connected Switches. * In STP/RSTP convergence starts as soon as there is a change in Topology/link fails. But now as we are grouping the links & treating them as 1 single link so even if one of the link goes down from a particular group convergence won't start. Convergence will take place only if the entire group/channel goes down. **Guidelines:** * All interface in an Ether Channel must be configured at the same Speed & Duplex. * All interface in an Ether Channel must support the same allowed range of VLANs. * In L2 Ether Channel, Interfaces must be assigned to the same VLAN/Configured as Trunk. * In L3 Ether Channel, IP Addresses must be assigned to port-channel logical interfaces. ### Ether Channel Protocols: #### PAGP (Port Aggregation Protocol): * Cisco Proprietary works only on Cisco Switches. * Has Desirable & Auto modes like 802.1Q modes. **LACP (Link Aggregation Control Protocol):** * Open Standard works on all the Switches. * Has Active & Passive modes like Active & Passive Modes of PAGP. ## Reference: * CCNA 200-301 OCG, Volume 1, Pg. 234 - Wendell Odom. * RST Notes *