# File lib/eui.rb, line 256
    def oui(options=nil)
        known_args = [:Delimiter]
        delimiter = '-'

        if (options)
            if (!options.kind_of? Hash)
                raise ArgumentError, "Expected Hash, but #{options.class} provided."
            end
            NetAddr.validate_args(options.keys,known_args)

            if (options.has_key?(:Delimiter))
                if (options[:Delimiter] == ':')
                    delimiter = options[:Delimiter]
                end
            end
        end
        oui = octets[0..2].join(delimiter)

        return(oui)
    end