Linksys WRT3200ACM (Openwrt), Vigor130 & Vodaphone

What you're trying to set up is trivial - however what makes following this a tad difficult, are the widely differing approaches necessary for <=19.07.x (swconfig based) or >=21.02 (DSA). Therefore I strongly suggest to update and start fresh (the wrt3200acm is a dual-firmware device, as long as you don't sysupgrade more than once, your original/ old firmware and its configuration remains untouched on the inactive partition set).

See Bananapi R2 snapshot build: no pppoe dialin and Configuration Issues OpenWRT 19.07.3 and DrayTek Vigor 130 - #4 by slh for reference of how to set this up using swconfig, DSA follows the same approach, with just minor (but essential) differences regarding the interface names and switch setup. Despite all this, I'd strongly recommend against throwing time into 'learning the old ways', just for being rewarded of having to do it the new/ DSA a few weeks/ months down the line.