Link aggregation (LACP) problems

Just reviving this old thread to post the solution. I have had weird network problem on and off, but I never correlated them to link aggregation configuration. But this morning only have of my network was reachable and links seemed to be severed asymmetrically (A can pin B, but B cannot ping A). I noticed that one of my aggregated links defaulted back to 100MB/s and after re-patching a faulty wire, nothing worked anymore.

It turned out that I had configured a static link aggregation, which is not supported by ReadyNAS. It should be a dynamic link aggregation, and the difference is not obvious in my switch's web front-end.

When configuring link aggregation on a LinkSys/Cisco SRW2024P for ReadyNAS, open a webpage, navigate to your Switch's web front-end and log in. Now select the 'Port Management'-tab and in there the 'LCAP'-sub-tab. Note: Do NOT create a link aggregation under the 'Link Aggregation'-sub-tab, as this will create a static aggregation.
In the 'LCAP'-sub-tab, enable the port you'd link to aggregate and select an identical LAG and priority for all of them:
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After clicking the 'Save Settings'-button, go to the 'Link Aggregation'-sub-tab. Here a new aggregation should appear with the LAG selected. The type should be 'LACP'. With the 'Details'-button, the aggregation can be configured and an name can be added. If the type says 'static', it's an old aggregation created in this sub-tab with the create button. This type is not supported by ReadyNAS.
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After clicking the 'Save Settings'-button, go to the 'Port Settings'-sub-tab. Here all ports assigned to the freshly created aggregation should state 'IEEE802.3x' under Flow Control. If this is the case, you have successfully configured a link aggregation compatible with ReadyNAS.
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