my %network = (
    '1.2.3.4' => {'1.2.3.5' => undef,
				  '1.2.3.6' => undef,
				  '1.2.3.7' => undef },
	'1.2.3.5' => {'1.2.3.4' => undef,
				  '1.2.3.6' => undef,
				  '1.2.3.7' => undef },
	'1.2.3.6' => {'1.2.3.4' => undef,
				  '1.2.3.5' => undef,
				  '1.2.3.7' => undef },
	'1.2.3.7' => {'1.2.3.4' => undef,
				  '1.2.3.5' => undef,
				  '1.2.3.6' => undef },
);