[FW1] Installation problems

["[iso-8859-1] Pablo Pérez" <pperez@myalert.com>]

    [ Part 1, Text/PLAIN (charset: ISO-8859-1 "Latin 1")  16 lines. ]
    [ Unable to print this part. ]

    [ The following text is in the "iso-8859-1" character set. ]
    [ Your display is set for the "US-ASCII" character set. Some ]
    [ characters may be displayed incorrectly. ]

    Hi all,
 
        I'm trying to install firewall-1 on a HP-UX 10.20. When I try to
configure the external interface I write "lan0" that is my external
interface name. However, after this change the configuration program asks
me for restarting and when I accept it shows an error message like this:
 
        "Unable to open /dev/fw0: No such file or directory
         Install: Operation failed: No such file or directory"
 
        I'm new at this mailing list and I would appreciate any help.
Thanks in advance,
 
                                    Pablo Pérez
                                    Myalert.com