Working Link Aggregation Config RT-AC87U?

[northwinds]

Hi all
Thought I'd open a new post for this as I'm not getting much response on the old
"Working Link Aggregation Config RT-AC66U"
post at
http://www.snbforums.com/threads/working-link-aggregation-config-rt-ac66u.12735/page-12#post-207691

Basically I've been following the suggestions in that thread and the LAGG wiki:
https://github.com/RMerl/asuswrt-merlin/wiki/Link-Aggregation
to try to get things working.

Everything does as it's supposed to except I lose ethernet after running "LinkAgg 3 4"

This is a real pain as it was the final deciding factor when I bought this router as I want to use the LAGG feature with my twin NIC nas4free box.

RMerlin came back to me saying
"Avoid LAN port 1, as it's not hosted by the Broadcom chipset."

This makes sense to me but I'm not sure how I would do this?

I'm presuming it would need something changing in the LinkAgg script?

Or do I just go "LinkAgg 2 3" or another set of numbers?

Would someone who understands that script please advise me what to chang as I'm afraid this is beyond me?

Many thanks!