How private networks talk to each other
I have two private networks linked by VSAT link without Internet. Only the second network has Internet access permitted by an ISP router. I want to permit the other network to access the Internet through the same ISP router.
Note that the network without Internet has the VSAT router as its gateway, and the VSAT router can access the other VSAT router through the remote site, which can also contact the ISP router.
But the Internet does not work from the remote site. What could be wrong and how can I fix it?
You have Network A (presume 192.168.1.xxx), which passes all the traffic as if it was one IP address (public) through a VSAT link [type of link is not that important]; at the other end of the link the VSAT connection talks to the members of Network B (presume 192.168.2.xxx -- could be anything except 192.168.1.xxx]. Since you did not specify domains, I will guess that workgroup and sharing files from workers in one group travel bidirectionally to and from workers in the other. In addition you have an ISP connection to Network B. You said "ISP router," which implies more than just a connection. I will presume a device allowing the local private addresses to be converted to public for using the Internet. The possibilities for not working are more numerous than the ways for it to work.
- The VSAT connection has port blocking enabled and Internet requests never get to the ISP router.
- The ISP router only sees the Network B addresses and ignores the Network A requests.
Considering bandwidth costs for VSAT, you should probably look at a local ISP for network A.
This was first published in September 2005