16.9 Reserved Addresses

Request For Comment (RFC) 1918 lists three areas of IP addresses that are "private." Private addresses are essentially non-routable and as such are available for use within a network without officially owning the addresses. The only potential problem is that if you use one of these three suites of addresses, gated is smart enough to not advertise them. This is not a problem if your clients are within the local area network. But if you have a more complex arrangement of networks, gated has to be specifically instructed to advertise these "private" addresses that you may have assigned to your cluster aliases. Use the "cluamgr –r resvok" command to inform aliasd and indirectly gated of your wishes. The reserved private address ranges are as follows:

                           10.0.0.0 - 10.255.255.255                         172.16.0.0 - 172.31.255.255                        192.168.0.0 - 192.168.255.255

This option should be used with caution. Setting any of these addresses as routable could potentially have major repercussions in a wide area network. While experimenting, we inadvertently managed to get access to a cluster member in Australia (from a machine in Georgia). Upon review, the cluster administrator had used this option without fully understanding its implications. His dynamic routers (on the same LAN as his cluster) were advertising access to several of the private addresses in the table above.