Today I received an allocation of IP6 addresses for some servers. I can 'play' with the last 2 of the 8 IP6 address segments. I always thought, mistakenly, IP6 was 6 segments, because it was IP6. IP4 had 4 segments. However IP6 is actually IP version 6 and it has 8 segments. The other interesting discovers are: :: means one or more 0 segments, example :: can mean 0:0:0: or just 0:0: or even 0:0:0:0: and, a real smile making favourite, is IP6 breaks Micro$oft's set-up. Micro$oft can not handle actual IP6 addresses because : is forbidden by Micro$oft in its 'Uniform Naming Convention (UNC) path names'. Naturally Micro%oft has invented a 'work around' solution. http://en.wikipedia.org/wiki/IPv6_address#Literal_IPv6_addresses_in_UNC_path_names Because : is sometimes used in an address to indicate the start of a port number, example http://www.anyonejunk.com:1234, the IP6 address can be enclosed within [ ] with the port number remaining outside the square brackets. How will IP6 affect the software in Centos and what gradual changes should one make on the transition to a major Internet change with the ending of NAT for IP4 addresses and a more secure (IPsec) end to end transmission protocol? -- With best regards, Paul. England, EU.