Search for duplicate data multidimensional array

I have an array in the following way:

Array
(
    [0] => Array
        (
            [IP] => 172.30.224.232
            [Equipo] => Space-saving
            [CodPat] => 111
        )

[1] => Array
    (
        [IP] => 172.26.35.108
        [Equipo] => Desktop Case
        [CodPat] => 11212
    )

[2] => Array
    (
        [IP] => 172.30.224.247
        [Equipo] => Space-saving
        [CodPat] => 123123
    )

[3] => Array
    (
        [IP] => 172.30.224.247
        [Equipo] => Space-saving
        [CodPat] => 2323232
    )

I have a cycle to extract the data from the IPs

for ($i=1; $i <= 255; $i++){
    $ip = "172.26.35.".$i;
    foreach ($ips as $val) {
    if ($val['IP']==$ip) {
        $existe = true;
        $equipo = $val['Equipo'];
        $codPat = $val['CodPat'];
        break;
        } 
    }
}

What I do not know how to solve is that it identifies duplicate IPs ... and try with functions like array_count_values (), array_map (), in_array (), etc. but I still can not get it to work like this ...

Any suggestions? Thank you!