After a three year stint with VoIP operations we're back to focusing on netflow-based monitoring.

So, the first thing I noticed is that recent versions of Perl have affected the operation of FlowViewer. Version 5.26 in particular has eliminated the current directory (.) from the default @INC array. FlowViewer depended on this to provide access to the common modules,, and FlowViewer installations using Perl v 5.26 or later will simply fail (e.g., see /var/log/apache2/error.log). There is a simple fix which requires moving those common files into an acceptable, secure, directory already available to @INC. Such directories can be found from the command prompt like this:

flowviewer@whiterose1:/var/www/cgi-bin/FlowViewer_4.6$ perl -V

I have moved the common files mentioned above into /usr/share/perl5 and created softlinks in the main CGI directory to point to them like this:
lrwxrwxrwx 1 flowviewer flowviewer 44 Oct 19 17:16 -> /usr/share/perl5/*
lrwxrwxrwx 1 flowviewer flowviewer 33 Oct 19 17:17 -> /usr/share/perl5/*
lrwxrwxrwx 1 flowviewer flowviewer 40 Oct 19 17:16 -> /usr/share/perl5/*