How to bypass VPN for local Network

Technical Support for Routers
1

My connection is:

Modem > main router (192.168.86.1/24) > GLMT300N (192.168.8.1/24) > NAS

I want NAS Internet to go through VPN while local computers attached to my main router can still access NAS.

Currently, after configuring OpenVPN, my local computers do not see my NAS. Reading through the forums, it seems iptables is an option… would you please help me configure it?

Edit: My current table:
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
default 10.24.0.5 128.0.0.0 UG 0 0 0 tun0
default 192.168.86.1 0.0.0.0 UG 0 0 0 eth0.2
10.24.0.1 10.24.0.5 255.255.255.255 UGH 0 0 0 tun0
10.24.0.5 * 255.255.255.255 UH 0 0 0 tun0
107.182.231.97 192.168.86.1 255.255.255.255 UGH 0 0 0 eth0.2
128.0.0.0 10.24.0.5 128.0.0.0 UG 0 0 0 tun0
192.168.8.0 * 255.255.255.0 U 0 0 0 br-lan
192.168.86.0 * 255.255.255.0 U 0 0 0 eth0.2
192.168.86.1 * 255.255.255.255 UH 0 0 0 eth0.2

2

I don’t think it causes by openvpn. Because of your NAS is intranet on GL-MT300N which gain ip address like 192.168.8.123, and the local computers which attach to your main router can’t see GL-MT300N intranet(192.168.8.x). Do you confirm it works without turn openvpn on?