I've got a similar issue to Allow two subnets to talk to each other over a wireless bridge
where my ISP's Modem/Router was the DHCP server and everything on my network was on the 192.168.1.x subnet, but I bought a second Netgear router to replace a Wifi repeater as I wanted a more reliable signal but also better parental controls.
Unfortunately to be able to use parental controls, the second router (connected to the ISP modem/router via Ethernet) forces me to configure it over a WAN connection to my modem/router and use a new 192.168.2.x subnet with it acting also as a DHCP server.
Now my devices connected to my modem/router on 192.168.1.x can't see everything else connected to the Netgear on 192.168.2.x.
What's the best way to resolve this? Configure both modem/router and Netgear router to use a subnet mask of 255.255.224.0? Or is there more to it than that? Sorry I'm at the limit of my networking knowledge!!
As per comment below, adding routing table screenshots... Routing Tables
Static route as defined in ISP router... static route
It's definitely a security issue - turned on logging for both dropped and accepted packages on the Netgear and can see the following as an example and 192.168.1.108 is the Squeezebox and 192.168.2.118 is the Squeezebox server - just can't understand why switching the firewall off doesn't resolve...
Apr 19 09:08:14 kernel: DROP IN=eth0 OUT=br0 SRC=192.168.1.108 DST=192.168.2.118 LEN=44 TOS=0x00 PREC=0x00 TTL=62 ID=2339 PROTO=TCP SPT=40533 DPT=3483 SEQ=2752079445 ACK=0 WINDOW=3000 RES=0x00 SYN URGP=0 OPT (020405B4)
Well I've tried everything I can think of - disable firewall, white listing the IP and still no luck...I also noticed the SPT (assume that's source port) changes in the log, so I added a whitelist range of 20000:50000 in the white list, but still packets are dropped??