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Trying to understand and make trunking / LAPC work, need words of advice.

Last Modified: 2012-06-27
So I have a NAS (Cisco NSS 324) that I am trying to connect to a Cisco SLM2048 switch, but I am having some issues that I need to understand:

•      On the NAS I have several different ways of using trunking. I thought that these are both Cisco products, that I could choose which ever one I wanted, and it would work. I have tried all except the last 2 ones, I don’t see any difference, and I am not sure which one is the best to use. Which one is the ‘always best option’ and which one is best for 2 cisco products to talk to eachother
o      Balance-rr (Round Robin)
o      Active backup (fail over)
o      Balance XoR
o      IEEE 802.3ad
o      Balance tlb
o      Balance alb
•      It seems that I can use Balance-rr regardless if I have set up port trunking on the cisco switch or not. Is this because the protocol supports working on 2 ‘normal’ ports in the switch, or should this not work?
•      On the cisco switch there are not very many settings to play with when you set it up. However there is one checkbox that says ‘LACP’, and in the instructions for the switch it reads:
o      “LACP — Enables or disables Link Aggregation Control Protocol (LACP). This box must be checked before the first port is added to the LAG”
o      I have successfully set up a LAG without having this checkbox first checked (well, kind of it worked for a while, and then transfer speeds went super low), what is this option, and why would I NOT want to have this box checked?
o      The instructions are very Spartan, so as I understand it
o      1 – check that box
o      2 – Pick the ports you want to LAG
o      3 - Save and it should work.
o      Is there something I am missing?

Here is the quick breakdown on how I set it up:

As you can see in image ‘LAG 3’ I basically check the ‘enable port trunking’ and choose one of the trunking modes, fill in the DNS and click save.
Then I go in to the switch, go to the aggrehation menu, and click the details button for the first LAG group (as you can see it has already been done in the picture LAG 1)
Inside this sub-menu (LAG 2.png) I choose the group number, give it a description, check the LACP box (as the instructions say), and pretty much leave things as they are, choose the two ports and click save & close.

Now it should work, yes? Is there anything I didn’t do or did wrong? It just seems there are so few settings that I could screw up.

Once I had this up and running the transfer speed was about 120 kb/sec, so something was wrong…
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