2
votes
2answers
74 views

Find out what Linux software is trying to phone home

I have seen some suspicious outbound communications blocked on my VPS, which hosts a small experimental Web site, and want to find out which application is making the attempt. The server is running ...
1
vote
3answers
250 views

Best practice for accessing management port of firewall

I'm in the process of setting up a bunch of servers at the other end of the world (well, 8 hours travel time) in a colocation place. The servers and firewall all have a remote management port (KVM, ...
-1
votes
2answers
140 views

Linux: Blocking outside attempts at attacking computer

in the past when I wanted to block outsiders from attempting to start connections with my Linux machine's various TCP services, what I was told to do was to add this line to /etc/hosts.deny: ...
2
votes
0answers
78 views

Shorewall stopped policies - routeback

Here goes a very specific question about the insides of Shorewall and Iptables in general. Shorewall supports configuration of "Stopped Policies" using the file routestopped, which defines the ...
2
votes
2answers
386 views

Mixing stateless and stateful firewall rules

I have been advised that mixing firewall rules that are both stateful and stateless can lead to trouble when it comes to troubleshooting. Is there any truth in this? Take the following two rule sets ...
2
votes
1answer
180 views

How are IaaS Virtual Machines Isolated?

I am currently examining Hypervisor firewalls for my graduate thesis, but I unfortunately don't have a lot of experience with IaaS environments. How are IaaS Virtual Machines network isolated from ...
4
votes
1answer
293 views

Exploited by newbie3viLc063s

My debian server got exploited by some scriptiekiddie who used Newbie3viLc063 http://pastebin.com/jma8JRG1 . Scriptkiddie uploaded logo_php.png to my server (My permissions sucked :s) and he did run ...
1
vote
3answers
840 views

Best practices for firewall hardware

I'm planning to implement a linux based firewall/router with at least 6 x 1Gb NIC's (network with ~300 computers/server with >=8 VLANs) Can anybody recommend hardware best practices (reference to ...
2
votes
1answer
167 views

Consequences of using -s and -d arguments in iptables

We are studying iptables for a Computer Systems Security course. We are confused as to what happens when the -s and -d arguments are both used in the same rule, such as: iptables -A OUTPUT -s ...
0
votes
2answers
416 views

Any open source software firewall with country based ip blocking feature? [closed]

I am looking for an open source firewall with country based ip blocking feature for Linux OS.
2
votes
2answers
3k views

IPTables DDoS protection working with per client IP address counter AND UDP

I am looking to protect LAMP server with a software, which will detect above average number of requests from single IP numbers (in this case DNS queries), and add these hosts to IPTables deny chain. ...
1
vote
2answers
619 views

How is iptables useful to prevent attacks against a LAN?

I need some advice securing a LAN using iptables. I've found lots of examples on how to secure single host with iptables, including scanning ports, attacking using ICMP-flood and TCP-flood. These ...
-2
votes
1answer
611 views

Linux tools to choose suitable Cisco ASA 5500

I have a linux webhosting server which affects a high DDOS. I want to use Cisco ASA 5500 Series Adaptive Security Appliances to protect the linux server from this DDOS. I know there are many factors ...
3
votes
1answer
694 views

Why ESTABLISHED,RELATED for INPUT only?

In many places and tutorials I see people add this line to their iptables: -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT And they do it only and only for "INPUT". What about OUTPUT and ...
4
votes
1answer
4k views

Fail2Ban does not ban failed root login attempt

I have a small server which only open ports are ssh, http and https. I have fail2ban installed and set up so that after 3 failed attempts someone gets blocked for 10 minutes (thats the dafault I ...
5
votes
4answers
17k views

Tips for a secure iptables config to defend from attacks. (client side!)

Own examples: ############### # KERNEL PARAMETER CONFIGURATION # PREVENT YOU SYSTEM FROM ANSWERING ICMP ECHO REQUESTS echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_all # DROP ICMP ECHO-REQUEST ...
1
vote
2answers
2k views

IPTables default security rules for a gateway/router?

On a router such as dd-wrt or tomato, what would be some default iptables rules? I am asking for rules on a router/gateway - For example; blocking SYN flood attacks, or XMAS attacks. The basic ...
3
votes
1answer
655 views

Firewall rules to block unwanted protocols on given ports

Does somebody has an idea, that what kind of iptables/pf rule must i use to achieve this?: i only want to allow these connections [on the output chain]: on port 53 output only allow udp - dns on ...