I have a NETGEAR WNDR4300 with atheros AR9344 rev 2, openWrt 19.07.7 and linux kernel 4.14.221. I'm using it as access point on a network with a powerful main router/modem 1 Gbit/s WAN. My aim is to increase WAN-LAN performance. In particular, I tried to disable many services (QoS/SQM, adblock, bcp38, transmission, minidlna, hd-idle, nlbwmon), but the only one that gave a significant performance increase was QoS/SQM (about 40 Mbit/s up/down).
At the moment I have enabled only (adblock and bcp38) and the access point achieves about 55 Mbit/s up/down. Can I disable the firewall from startup service? Is there something more that I can do?
Have you considered reverting back to stock firmware, since you are using it as an AP anyway?
if you have a primary modem/router, with a FW, the WNDR shouldn't really do anything else but AP - https://openwrt.org/docs/guide-user/network/wifi/dumbap
Doesn't however stop if from running all the other services except perhaps QoS/SQM, but also depends on the configuration options in your main modem/router.
I prefer using openWRT since it uses a newer kernel and has many security weaknesses solved.
Does this mode allows to increase performance? Moreover, can I still run adblock, banIP and custom DNS?
Depends on what you're capable of configuring in your main router.
Banip wouldn't work, because it probably requires a firewall.