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etherchannel port aggregation

Why the maximum total no 8 port(cable) can be loggicaly bundled in etherchannel?

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Re: etherchannel port aggregation

Hello,

I'm not 100% sure about this, but I think the number is 8 ports, due to load-balancing formula. The port is selected using a Cisco-proprietary hash algorithm, based on  source or destination MAC addresses, IP  addresses or TCP and UDP port numbers. The hash function gives a number between 0 and 7, and the  following table shows how the 8 numbers are distributed among the 2 to 8  physical ports. In the hypothesis of real random hash algorithm, 2, 4  or 8 ports configurations lead to fair load-balancing, whereas other  configurations lead to unfair load-balancing:

Number of Ports Load Balancing
81:1:1:1:1:1:1:1
72:1:1:1:1:1:1
62:2:1:1:1:1
52:2:2:1:1
42:2:2:2
33:3:2
24:4

I hope this helps you!

Cheers,

Calin

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