1. Get the original
   ftp://ftp.appli.se/pub/isakmpd/isakmpd-1.0.1.tar.gz

2. Unpack the original
   $ tar -xvzf isakmpd-1.0.1.tar.gz

3. Change directories down into the upper level directory of the package
   $ cd isakmpd-1.0.1

4. Apply the patch:

   $ patch -p0 < isakmpd-1.0.1.diff

5. Fix the permissions as per the modfile:

ir-diff-dist notice: chmod instructions for the end-user are:

chmod ogu+x config.guess config.sub configure install-sh missing mkinstalldirs