Automatic assignment of addresses in a computer communications network

A communications network apparatus, comprising:

• means for storing an end system identifier, ESI, of said apparatus in a first non-volatile memory;
• means for storing a default value of a prefix in a second non-volatile memory;
• means for using said default value of a prefix as a stored prefix, said default value of a prefix used as said stored prefix when said apparatus is manufactured;
• means for setting a manual flag in said apparatus, said manual flag capable of having a first logic value, and capable of having a second logic value;
• means for setting a trusted flag in said apparatus, said trusted flag capable of having a first logic value, and capable of having a second logic value;
• update means for said apparatus to update an address assigned to said apparatus;
• selection means for selecting a prefix during an event when said update means performs an update of said address assigned to said apparatus, said selection means responsive to said manual flag and responsive to said trusted flag as follows,
• ______________________________________ value value action of of manual trusted flag flag first first wait for manual configuration logic logic value value first second wait for manual configuraiton logic logic value value second second IF a trusted neighbor exists logic logic adopt a neightbor prefix of said value value trusted neightbor as a designated prefix store said designated prefix as said stored prefix set said trusted flag to said first logic value ELSE (no trusted neighbor exists) set said designated prefix to said stored prefix second first set designated prefix to said logic logic stored prefix value value ______________________________________
• address forming means to combine said designated prefix with said ESI of said apparatus, said designated prefix and said ESI forming at least a part of an address of said apparatus.