my @list_UST = ( "192.168.17.4", "11.255.22.1", "10.256.17.13" );

my %found;

for my $ip (@list_UST) {
    $found{$ip} = glob("*_${ip}_*.log");
}
say "Gefunden: ", join ",", grep { $found{$_} } sort keys %found;
say "Fehlend: ", join ",", grep { !$found{$_} } sort keys %found;