Hello folks,

Now I must admit that I'm a dummy: I installed fireflier-client-gtk but I can't the thing started.
I get a warning: (fireflier-client-gtk:6880): Gtk-WARNING **: cannot open display:

Now what does that mean?

Anyways, I must do something with iptables to secure my pc, and I thought that this was a tool to make rules for iptables.

Who knows???

Best regards,

sjonnie48

Gtk-WARNING **: cannot open display:
You need to run a graphical windowing system (X11/Xorg) (or you need to adjust xauth but I doubt that's the case).


Anyways, I must do something with iptables to secure my pc, and I thought that this was a tool to make rules for iptables.
Have a look at LQ's Tutorials or the LQ FAQ: Security references, post #2 "Netfilter, firewall, Iptables etc " for tutorials about the firewall and some example scripts. Else just post what services you run and would like people to have access to and we'll work it out.

Thank you for your reply. In the meantime I have figured out why I received the Gtk-warning.
One must be logged in as root, and kubuntu has initially blocked a root login.
To enable the root login I edited one line in /etc/kde3/kdm/kdmrc: AllowRootLogin=true.
After that I was able to login as root, but that was not the end of the misery.
When I ran with the X-server as root, the environment looked terrible. Windows look like splash-screens: no buttons and no menubar. Also I received some error messages which I could not read. It seems as if the developers of kubuntu want to discourage users to work as root with the X-server.
So I think it is better to work in a shell within the X-environment with my favorite konsole.

My demands for security are the following: my new computer is going to be a router for a small home-network, and it will also act as an ftp-server.
For that purpose it has two ethernet cards, eth0 for the connection with internet, eth1 being the routing connection to a switch which connects my other computers, and guests with a laptop.
I want my computer/router to be invisible for the world, which means that icmp pings should be ignored, and all ports blocked for unrequested incoming traffic.
This is the first time for me, so some advice is quite welcome.

Best regards,

sjonnie48

For your router question have a look at Ipcop, m0n0wall, Shorewall, SmoothWall and such and please set up separate threads in Linux - Networking for routing and filtering (iptables) and when you got that going one in Linux - Security for hardening. You also might want to start reading post #1 of the LQ FAQ: Security references.