I want to use my router to bridge 2 networks that I have, 192.168.20.1 and 192.168.25.1 I need to joint these into the same network, I have many camera on .20 to be accessible from .25, cam you help me to know how to program the router to link these to network together, did I need to add Vlan. If so can you help me with example
Join these /24 nets in one 192.168.16.0/20(192.168.16.0-192.168.31.255) or route them on the router.
As you said, they are connected to the router, then router already know about them as connected directly to him.(192.168.20.1 and 192.168.25.1 addresses are on router). On each camera have to be default gateway to other network.
Thanks,
But let say we have two different network like 10.1.101.1 and 192.168.20.1, how can I bridge these 2 networks to be accessible. From 10.1.101 to 192.168.20 and revers.
Thanks
Without router, you can’t merge them, it’s illogically. Bridge can merge layer 2 segment in same network, not layer 3. You can point as a router, the host in 10.1.101.0/24 network, which also connects to 192.168.20.0/24. Then, this host(PC) can be the router. You will need to add a route on host 10.1.101.1 to 192.168.20.0/24 network and host 192.168.20.1 must have a route back to 10.1.101.0/24. But better put a router between them 
The request is not clear.
The initial question seemed to ask how to join two LAN networks behind the same router. By that I mean they can all talk together but maintain their separate IP schema.
(It would be easiest to put them all on one LAN but should be doable anyway).
The next question seemed to ask how to join two LAN networks behind two different routers?
Which is it?
In the first question, I would have thought that if they are all on the same bridge, they should all see each other.
If not then identifying both has LAN interfaces would do the trick…
The second question sounds like its suited to a VPN scenario or EoIP scenario…
Better post a scheme