Linux - SecurityThis forum is for all security related questions.
Questions, tips, system compromises, firewalls, etc. are all included here.
Notices
Welcome to LinuxQuestions.org, a friendly and active Linux Community.
You are currently viewing LQ as a guest. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features. Registration is quick, simple and absolutely free. Join our community today!
Note that registered members see fewer ads, and ContentLink is completely disabled once you log in.
If you have any problems with the registration process or your account login, please contact us. If you need to reset your password, click here.
Having a problem logging in? Please visit this page to clear all LQ-related cookies.
Get a virtual cloud desktop with the Linux distro that you want in less than five minutes with Shells! With over 10 pre-installed distros to choose from, the worry-free installation life is here! Whether you are a digital nomad or just looking for flexibility, Shells can put your Linux machine on the device that you want to use.
Exclusive for LQ members, get up to 45% off per month. Click here for more info.
I'm not entirely sure that this is the correct place to post, but it seemed like it so here goes....
I am pretty new to linux in general. I am a network admin in training and i just finished setting up a DNS caching only server on my internal network, which is behind a pretty decent firewall. I would like to block all the ports that i don't need to use on my caching DNS server. Would I use iptables to set this up? I don't want anything complicated. I just want my 'firewall' to say "don't let anything in unless it's on these 6 or 7 ports". thanks.
Distribution: FreeBSD,Debian, RH, ok well most of em...
Posts: 238
Rep:
hmmmm not sure if I am a fan of putting a firewall on every server. If this machine is behind a firewall you may complicate things more if anyone wants to add say DHCP to this server. Lock it down and disable everything you don't need to be running.
edit /etc/services file and hash out all ports in that file EXCEPT the port you want it to listen on e.g 53 for DNS. use either netstat -a to check all ports that listening and chkconfig --list. Once services and ports have been id then disable them or remove them.
There are other ways of doing this but this should doit
Originally posted by cyph3r7 hmmmm not sure if I am a fan of putting a firewall on every server. If this machine is behind a firewall you may complicate things more if anyone wants to add say DHCP to this server. Lock it down and disable everything you don't need to be running.
check the stickys above for more info........
wow, why not put a firewall on every server? if your firewall gets cracked, then that leaves all of your other servers butt naked to an attack. firewall everything is my motto. you never put all your eggs in one basket. if they wanted to add a DHCP server to it, editing a firewall script should be easy if they are capable of adding the server.
this would especially be the case if you have clients on your network behind the firewall with you that belong to Kazaa users.
Last edited by Robert0380; 09-19-2003 at 08:46 PM.
No kazaa, but my net admin certainly knows how to set up DHCP and how to do any firewalling and/or poking holes in our firewall as is necissary. I don't though....which is why i'm learning anyways, i am still working on this, i'll let you know if i have any more questions.
LinuxQuestions.org is looking for people interested in writing
Editorials, Articles, Reviews, and more. If you'd like to contribute
content, let us know.