08-12-2008 11:42 PM - edited 03-06-2019 12:46 AM
Hello,
on a Cisco Etherchannel or LACP Channel, with configured src-dst-mac Balancing, wich algorithm use Cisco IOS for the Port foward desicion based on Source und Destianion MAC Adr. or Source and Dest. IP Adr (for a src-dst-IP Balancing)?
Thanks?
08-13-2008 12:03 AM
Hello Juergen,
it is a bit level EXOR of last significant bits of source and destination address
the result of the EXOR of the last m bits is used to point to the member link of the bundle
if using two links is only the exor of the last bit (less significant bit)
if using four links is the exor of the last two bits (index 00 to 11)
if the number of links is odd they use one more bit
example : 3 links it uses the last three digits here 3/8, 3/8 2/8 are mapped to the three links
Hope to help
Giuseppe
08-13-2008 12:14 AM
Hello Guiseppe,
thanks for the answer!
I have tested a 2 Channel Link with the 2 Client Mac-Adr., the less significant bit: Client 1: ....3F and Client 2: ....A7, Dest Mac is ....24.
In this case Client 1 traffic should be forwarded on Channel-Port 1 and Client 1 traffic should be forwarded on Channel-Port 2!
But only Channel-Port 1 is used!
We find out that on a 2 Link channel, not only the less significant bit is used for the forwarding desicion?!?
08-13-2008 05:32 AM
Hello Juergen,
binary digit EXOR of last bit
3F => 0011 1111
A7 => 1010 0111
last bit client 1 : 1
last bit client 2: 1
dest mac 24 => 0010 0100
last bit dest = 0
0 exor 1 in both cases so it is right what you see only one link is used in this case
Hope to help
Giuseppe
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