Use this build dd-wrt.v24-42502_NEWD-2_K3.x_mega.bin
Installs over current DD-WRT firmware. You should do a 'reset' after the install just cause I have NO idea what your current setup is.
use next DD-WRT public release should work also.
Works okeydokey as a 'Repeater' connected to my main net. --- some pics below.
only connected to its VAP with my pissy old phone
Asus RT-N12B ... I promise this is an ASUS RT N12D1 ---just shows as RT-N12B using this firmware :')
DD-WRT v3.0-r42502 mega (02/24/20)
Linux 3.10.108-d10 #2544 Mon Feb 24 16:46:35 +04 2020 mips
## Save as Startup in webif page ../Diagnostics.asp so VAP will work correctly after a router reboot: ##
wlconf eth1 down
wlconf eth1 up