Tagged Questions

2
votes
1answer
33 views

ufw firewall rules for security.debian.org

What is a practical way to manage a whitelist of firewall outgoing connection rules for http://security.debian.org (on a server that blocks all outgoing connections by default)? My understanding is ...
0
votes
1answer
49 views

Iptable rule to ssh over the internet

I've a server abc.example.com and a remote desktop zzz.example.com. I'm using SSH over a custom port, say, 6789. Whenever my firewall is off, I'm able to connect to the server successfully. But, as ...
1
vote
2answers
441 views

iptables blocking from internet side on eth1?

How to use iptables to deal with two Ethernet ports? eth0 port for LAN use (192.168.1.50 Private IP). eth1 port is connected to the internet via cable modem (80.0.xxx.xxx public IP). ifconfig ...
-2
votes
4answers
193 views

Steps to secure your server? [duplicate]

Possible Duplicate: What to use to harden Linux box? Apparmor, SELinux, grsecurity, SMACK, chroot? I'm just completed install my web server. So what should i do to secure it? I just ...
3
votes
2answers
1k views

How can I block a range of IP addresses with an Amazon EC2 instance?

I know a certain range of IP addresses are causing problem with my server, 172.64.*.* what is the best way to block access to my Amazon EC2 instance? Is there a way to do this using security groups or ...
10
votes
4answers
1k views

Why do we need a firewall if no programs are running on your ports?

When I try to telnet to a port on a server, and if there is no program listening on that port telnet dies with a "Unable to connect ... " error. I understand that. But, why do we need a firewall if ...
2
votes
1answer
317 views

UFW Limit does not appear to work

I have my ssh port changed to XXX. Then I did ufw limit XXX/tcp However, when I try to login, after 5/6 failed attempts I get thrown back to prompt, but I can try again. Is that supposed to be the ...
2
votes
3answers
942 views

Making sense of auth log

I am seeing some log enties that look like hacking attempts Type 1 Dec 26 03:09:01 ... CRON[9271]: pam_unix(cron:session): session closed for user root Dec 26 03:17:01 ... CRON[9308]: ...
0
votes
1answer
1k views

How to really security a linux-mint-desktop?

I'm installing some security software in my mint9Gnome. I first went to Firestarter and looks like a pretty start. Now I'm going to OSSEC and want some good tools to search my logs too. Thinking ...
-1
votes
1answer
2k views

What is sport and dport?

I want to stop internet on my system using iptables so what should I do? iptables -A INPUT -p tcp --sport 80 -j DROP or iptables -A INPUT -p tcp --dport 80 -j DROP ?
2
votes
1answer
828 views

iptables rule to allow access to internet

I made default policy of my machine- iptables -A INPUT -j REJECT #DROP ALL PACKETS TO INPUT CHANNEL INPUT channel has been blocked. Now I want to allow only some specific services like I should be ...
2
votes
2answers
319 views

Security with Kernel IP Forwarding Enabled

I recently enabled IP Forwarding on a production web server that also acts as a VPN server. What, if any, security issues did I just set myself up for? And are there any iptables rules I should set ...
6
votes
4answers
3k views

Fail2ban block with IPtables doesn't work on Debian Lenny. [moved ssh port]

I've recently decided to do some security maintenance. I saw my logs, and there were some tries against my SSH server. At first, I moved away the SSH port from the default 22. After it, I read ...
5
votes
1answer
336 views

Opening port 80 but remain secure

I have a standard installation of Ubuntu 10.04, and have installed the LAMP stack so I can do some web development locally. On my router I have opened port 80 so I can develop with external services ...
3
votes
1answer
160 views

Linux App that monitors log and add rules to iptables

I used to use a linux software that monitors logs like http, ssh, etc and if it detects that someone is trying to use brute force, it blocks that ip by adding a rule to iptables. I forgot what that ...
3
votes
3answers
237 views

Turning an old computer into a network firewall

I have an old Dell Dimension with two ethernet cards, and I need to turn it into a firewall. I've tried FireStarter and IPCop, but I don't think I'm setting them up right. Here's the setup that I'm ...
0
votes
2answers
128 views

Where to handle packets between clients?

"Server": 192.168.1.1 I want to "theoretically" disable that the clients can "ping" each other. Can i use an iptables rule for it? e.g.: iptables -A FORWARD -m iprange --src-range ...
1
vote
1answer
848 views

IPTABLES rule for separating users

I have an OpenWrt 10.03 router [ IP: 192.168.1.1 ], and it has a DHCP server pool: 192.168.1.0/24 - clients are using it through wireless/wired connection. Ok! Here's the catch: I need to separate ...
5
votes
4answers
2k views

Debian: Which firewall for a newbie?

I have to install a firewall on my server (so without X Server). It's a debian lenny. If it is possible, I want to avoid the use of iptables. Is there a way to install/configure a firewall for a ...
2
votes
1answer
299 views

Learning about iptables: Is this Slicehost example any good?

In preparation to eventually launch my first website, I've been playing with Ubuntu Lucid Server in a VM on my WinXP machine. I've been alternating between the Linode and Slicehost tutorials/articles ...