Etherchannel on a P55A / TSm Backup

[lindgreen]

Hello guys,

Has anyone experiences with the troughput of e.g. 4 gigabit adapters put together to an etherchannel? Is the bandwith really 4 times faster or is there a loss because of overhead for e.g. the load balancing?

Regards,
Peter

 

[hirschaj]

Etherchannel does not create a bigger pipe for you. It just provides adapter redundancy. Your throughput with 4 gigabit adapters in an etherchannel should be roughly the same as with 1 gigabit adapter alone.

Jim Hirschauer

http://www.aixexpert.com

 

[lindgreen]

Hello,

thanx for your fast answer...
Are you sure???
If yes then i understood something completely wrong in the documentation about it:

"The main benefit of EtherChannel and IEEE 802.3ad Link Aggregation is that they have the network bandwidth of all of their adapters in a single network presence."
Link:

http://publib.boulder.ibm.com/infoc...aix.doc/aixbman/commadmn/tcp_etherchannel.htm

regards,Peter

 

[hirschaj]

Yes, I am sure. Only 1 adapter is used at a time. The load will get spread across all of the adapters in the etherchannel, but not in parallel. There are a few diff algorithms you can choose to determine exactly how the load will get spread. Also make sure your switch is capable of handling the etherchannel config.

Jim Hirschauer

http://www.aixexpert.com

 

[lindgreen]

Ok, thanx for the tipps...
regards
Peter

 

[hfaix]

Jim is right. etherchannel is typically run in a "fail_over mode". You could look into aggregating the adapter(s). I've never done it, but have seem posts on here about it.

 

[p5wizard]

What I've read about it is you can have etherchannel configured as fail-over and as link-aggregation. Not sure, but I believe you can have both at the same time also (e.g. 3 adapters link-aggregated and one extra adapter in standby). You do need a network switch that is configured for this.


HTH,

p5wizard

 

[lindgreen]

When my network collegues have time i would try it on my tsm server. I have two gigabit adapters in it and they are attached to a cisco enviroment. I would see it myself now Thanx you for your informations about it.

 

[p5wizard]

read this first:

http://publib16.boulder.ibm.com/pseries/en_US/aixbman/commadmn/tcp_etherchannel.htm

HTH,

p5wizard