etherchannel and load balancing method

[sarahr202]

Hi everybody

If we configure ( switch)# port-channel load-balance src-dst-ip

and we have:

src ip 199.199.199.1

dst ip 199.199.199.2

1 binary 001

2 binary 010

001

010

------ XOR

011

Which means link 3 will be selected in etherchannel to send the packet.

Now let say we have a switch with 8 ports bundled as etherchanel and we configure the following:

sw(config) port-channel load-balance src-ip

Let say src ip is 199.199.199.1

How is XOR operation performed in above case considering we have one input ( i.e src ip) for XOR operation ?

thanks and have a great weekend

[rsimoni · Accepted solution]

Hi Sarah,

the hashing mechanism on Cisco switches is far more complicated than XOR.... morevoer its implemantation differs across different platform.

Bottom line the hashing being used is Cisco proprietary and cannot be disclosed, sorry.

Riccardo

[Joseph W. Doherty · Accepted solution]

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Posting

You might find of interest:

http://www.cisco.com/en/US/tech/tk389/tk213/technologies_tech_note09186a0080094714.shtml

http://www.cisco.com/en/US/tech/tk389/tk213/technologies_tech_note09186a0080094646.shtml

The sup2t offers improved etherchannel hashing; an 8 bit hash.