Install the latest openssl libraries:

apt-get install libssl-dev  

Install all files necessary to recompile the kernel and install the driver (as root user):

apt-get install kernel-package
apt-get install libncurses5-dev
apt-get install linux-source-2.6.32
apt-get install tcsh
apt-get install rpm
apt-get install libssl-dev
apt-get install psmisc
 

Get the latest RealPort driver and put it in a convenient directory

https://ftp1.digi.com/support/beta/linux/dgrp

Make a deb install package:
 

rpmbuild --rebuild 40002086_X.src.rpm
alien --scripts dgrp-(version).src.rpm

This will create file dgrp_(version+1)_(architecture).deb

 Install the .deb file:

dpkg -i dgrp_(version)_(architecture).deb

Set up the port server at a known IP address and number of ports

dgrp_cfg_node -v -v init aa 192.168.1.1 16

This will set upa a 16 port Digi PortServer at the given address, and name the devices:

/dev/ttyaa00 to 15 and /dev/praa00 to praa15 (transparent printing devices)

Start the daemons at boot-up:

update-rc.d  dgrp_daemon  defaults 22
update-rc.d  dgrp_ditty  defaults 22