problem with broadband connection

RouterOS Forwarding Protocols
1

hello everybody

i connect three network to each interface of mikrotik router each pc in any of them can ping the others
every thing is good but when i connect broadband connection in a pc other pc in other network can not ping it
whats the problem
thanks

2

so are you trying to NAT the networks ?
provide some basic map of the network, IP Addressing and Subnetting