I am using Shorewall with my Mandrake 9.0 box and have just done a port scan on my system. I found that Ports 53 & 139 were accessible to the outside world and curious how do I go about closing these off to make it more secure?
From what I understand 53 is DNS and 139 is Samba which could be rather dangerous if it's in the same sense as the Port 139 on a Windows box.
I am using Webmin to modify rules, the fules I have setup currently looks like the following
I know they are a little messy especially the one's for samba but I haven't as yet worked out how to only allow only local area traffic through which is a little later on in this post.
I don't really understand what all these zone net, zone fw, zone masq etc mean so I'm after a bit of help perhaps someone pointing me in the right direction or even explaining them, I am not afraid or reading as I have done plenty of that recently.
While I am at it, is there anything else I should close off.
Actually how can I go about setting up the firewall so I can block everything from the outside except ports I want perhaps an ftp or http server and leaving the inside wide open for PC's on the lan since they all belong to myself or the family and security isn't really an issue.
Any help would be great