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EtherChannel

Fast Ethernet and Gigabit Ethernet interfaces cannot be combined into a single EtherChannel interface. The interfaces must all be of the same type. For an EtherChannel to be created, the ports on the two switches must match the speed, duplex, and VLAN information.
When a non-Cisco device that does not support DTP is connected to a Cisco device that supports DTP, the commands switchport mode trunk and switchport nonegotiate have to be entered on the respective interfaces in order to create the trunk between the two connected devices
EtherChannel Mode
Description
PAgP
Cisco Proprietary protocol
LACP
Open Standard used by most of Vendors
ON
Forced to form Etherchannel without using negotiation protocol
PAgP Mode
Desirable
Auto
Desirable
Yes
Yes
Auto
Yes
No
LACP
Active
Passive
Active
Yes
Yes
Passive
Yes
No
Etherchannel Modes Comparison
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Feature
PAGP Mode
LACP Mode
On Mode
Full Name
Port Aggregation Protocol
Link Aggregation Control Protocol
Static Mode
Standard
Cisco proprietary
IEEE 802.3ad
None (Static configuration)
Compatibility
Cisco devices
Multivendor, IEEE standard
Limited, depends on vendor support
Negotiation
Yes
Yes
No
Modes
Auto: Passive, waits for PAGP packet Desirable: Active, sends PAGP packet
Active: Sends LACP packets Passive: Waits for LACP packets
On: Forces aggregation without negotiation
Load Balancing
Supports
Supports
Supports
Fault Tolerance
High
High
Low
Configuration Complexity
Medium
Medium
Low
Dynamic Link Addition/Removal
Yes
Yes
No
Loop Prevention
Yes
Yes
No
Multivendor Support
No
Yes
No
# Manual
int range gi0/0-1
	channel-group 1 mode on
	
# LACP
int range gi0/0-1
	channel-group 1 mode active

# PAGp
int range gi0/0-1
	channel-group 1 mode desirable
	
show etherchannel summary

show interface port-channel 1

show lacp counters

show lacp internals

show lacp neighbor

lacp rate fast

port-channel min-links

lacp max-bundle

show lacp sys-id / lacp system-priority (global - lower is better)

lacp port-priority (interface - lower is better)

lacp fast-switchover (faster failover than STP)

show etherchannel port
port-channel automaticly adjusts bandwidth
LACPDUs - Slow every 30 seconds, Fast every second. Removed from bundle after missing 3.
Both switches need to be on the same.
links in bundle should be multiple of 2 for load balancing efficiency
Default switch priority 32768, lowest is master
Interface status suspended - issue with etherchannel