Proper network design? I have a few questions for the group that maybe someone can answer. From my studies when I got CCNA certified, I understood that different networks were ALWAYS separated by a router. At my company we have this equipment that was purchased several months ago that acts as a digital cellular network. It was set up and was able to operate, but only in a limited way. Basically, this is the setup - the digital cellular network was on the 192.168.2.0 subnet (subnet mask 255.255.255.0). The company development LAN was on the 192.168.0.0 subnet (subnet mask 255.255.255.0). The two small networks (less than 10 hosts in each subnet) were all tied together at a 24 port hub. The gateway to the Internet was through a Linux box. The digital cellular network was basically a box (with IP address 192.168.0.100) that passed packets to network 192.168.2.0 through a low power transmitter to the cellular hosts in the 192.168.2.0 subnet. With this setup, only one desktop host on the 192.168.0.0 network could communicate to the 192.168.2.0 cellular network (desktop host 192.168.0.20). The problem of only one desktop host in the 192.168.0.0 network being able to communicate with the 192.168.2.0 network was solved by replacing the Linux box with a Cisco 2514 router (with two ethernet interfaces). The configuration for the router was exactly the same as the Linux box except for one small addition. The following line was added as a static route:
ip route 192.168.2.0 255.255.255.0 192.168.0.100 Now let me ask you, have you ever seen a router that gets a packet on one interface pass it right back out the SAME interface back to another host on that same network? Our setup basically ties two DIFFERENT class C subnets together through a hub and the Cisco router makes it all work perfectly. This doesn't sound like standard network design as I've seen it described in any text so far. I'll describe it a little more for clarity. If i'm on a desktop PC (IP address 192.168.0.20) and ping IP address 192.168.2.2, windows will send that packet to the default gateway (configured as 192.168.0.1 in windows network applet - which is the Cisco router) since it lies in a different network (since the subnet mask is 255.255.255.0). The Cisco router receives this packet destined for the 192.168.2.0 network and since it matches it with the above static route, sends it back out the same interface it came in on, back to another host (192.168.0.100 - the cellular transmitter box) out to the cellular host (192.168.2.2). This is the way the cellular network equipment manufacturer intended it to work. The setup works, but it sounds really weird and nonstandard. Has anyone else encountered such a setup or something similar before? Is this a kind of network design that is done often? Doesn't a router normally always route packets from one interface to another? Thanks in advance for your responses. Frank Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=49536&t=49536 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
