my @sortedIdx=
        map { unpack "N", substr($_,-4) }
        sort
        map {
            my $key = $oids{ifName}{$_};
            $key =~ s[(\d+)][ '0' . pack "N", $1 ]ge;
            $key . pack "CN", 0, $_
        } keys %{$oids{ifName}};

##</code><code>##

my @keys= ( keys %{$oids{ifName}} )[
        map { unpack "N", substr($_,-4) }
        sort
        map {
            my $key = $oids{ifName}{$_};
            $key =~ s[(\d+)][ '0' . pack "N", $1 ]ge;
            $key . pack "CN", 0, $_-1
        } 1 .. keys %{$oids{ifName}}
];