Here is one way to do it. This example changes $/ to read the records one at a time. The regex may need to be extended a little and you could use an array instead of a hash.

    #!/use/bin/perl -w

    use strict;

    my %ports;

    $/ = "#-------------------------------------------\n";

    while (<DATA>) {
        chomp;
        $ports{$1} = $_ if m/^\s+Port (\d+)/;
    }

    print $ports{120};



    __DATA__

    Port 119 NNTP

    * Microsoft Ports-Microsoft Exchange ...
    * RFC977
    * RFC1036

    #-------------------------------------------

    Port 120 CFDP

    (UDP) Coherent File Distribution Protocol (CFDP)

    * RFC1235

    #-------------------------------------------

    Port 123 NTP

    (UDP) NTP (Network Time Protocol)

    * RFC2030
    * RFC1129
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--
John.