Chapter 13. Network Administration248 PACSystems* RX7i & RX3i TCP/IP Ethernet Communications User Manual GFK-2224QExample: Two Networks Combined into a SupernetSupernetting is a technique used to combine two smaller networks into a larger network by extending the hostportion of the subnet mask and reducing the network portion. Supernetting works only with adjacent networksthat share the same network id value , such as networks 1 and 2 in this example.As with subnets, the subnet mask is used to divide the IP address into a custom netid portion and hostidportion.For example, the two networks 10.0.117.0 and 10.0.116.0 can be combined into a larger 10.0.116.0 network ifthe subnet mask 255.255.254.0 is applied to both addresses.11111111 11111111 11111110 00000000 = 255.255.254.0netid bits hostid bits subnet mask(dotted decimal)(binary)Figure 105: Subnet Mask Used to Effect a Supernet10.0.116.1Network 110.0.117.1 10.0.117.210.0.117.3Network 210.0.116.2GatewayGAB CFigure 106: Resulting Supernet
