are they switches or routers?
If you are using 2 routers, then they are 2 different IP segements. If these are 2 SOHO nat routers, then it's going to be very tough to do with 2 NAT/ROUTED segements. Instead, setup one of those as a dummy switch (turn off DHCP, don't use the WAN port, go from LAN to LAN port between the 2 routers)