You probably want something like:

sub _print_nodeandip {
    my @ips;

    open my $FILE_FH, '<', $File or die "Failed to Open File $File for
+: $!";

    while ( <$FILE_FH> ) {
        my $node = ( split /,/ )[ 1 ];

        if ( $node =~ /^(?:MS|TS|BP|Dummy)_([[:alnum:]]+)_[[:alnum:]]+
+_(?:0001(?:_[[:xdigit:]]{4})?|[[:xdigit:]]{4})$/ ) {
            print "$1\n";
            }
        }
    }
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