-4
votes
1answer
29 views

Because when I open ports with iptables appear closed

I opened the following ports with iptables on Debian 7: iptables -X iptables -F iptables -P INPUT DROP iptables -P FORWARD DROP iptables -P OUTPUT ACCEPT iptables -A INPUT -m state --state ...
0
votes
1answer
51 views

How do I test my firewall rules?

I've setup some rules in ufw and I've turned it on. Now I want to ensure my rules actually block traffic. However, when running nmap -PN -p <my_port> <ip> from my local workstation it ...
2
votes
1answer
90 views

nmap lists host as up despite being black listed

I have an iptables rule setup that marks addresses as suspicious if they connect on certain ports or any unopen ports. If more than three consecutive connections are made without authentication, then ...
-2
votes
2answers
528 views

Ports do not open after rules appended in iptables [closed]

I have a server that I am trying to setup for OpenVPN. I have followed all the steps, but I see that when I try to connect to it in Windows, it doesn't allow me, it just hangs on connecting, so I did ...
1
vote
1answer
737 views

Port 443 is open but IP tables denies it

When I run the following command on my Ubuntu instance: $ nmap host I see that port 443 is open: Starting Nmap 5.21 ( http://nmap.org ) at 2013-03-19 05:36 PDT Nmap scan report for [host redacted] ...
3
votes
1answer
1k views

Using nmap to scan open ports. iptables default policy affects other rules?

I'm trying to find out why changing my default iptables policy is affecting what nmap sees when it scans my host. Consider the following iptables setup: iptables -F iptables -A INPUT -p tcp -s ...
2
votes
2answers
938 views

IPtables: is there a minimum UDP packet size for a DNS lookup?

IPtables for a virtual dedicated server. I would like to block UDP scans and I was wondering whether there's a minimum packet size for a DNS lookup? Nmap sends 0-byte UDP packets (source : ...
0
votes
1answer
171 views

nmap external localhost with iptables

I have a status monitor that I wish to set up using nmap to show all my externally open ports. Naturally nmap came to mind. Unfortunately I use an iptables firewall and allow all traffic on the ...
0
votes
1answer
3k views

iptables has port 80 open but nmap shows it closed

I'm having some troubles getting a Debian webserver to open up port 80 for HTTP traffic. In my iptables, I opened up port 80 using the following commands: iptables -A INPUT -p tcp --dport 80 -j ...
2
votes
1answer
2k views

Why does nmap report different results from localhost?

When I execute "nmap -sT -O localhost" per the Centos 5 deployment guide, I get: Not shown: 1677 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 8080/tcp open http-proxy ...
1
vote
4answers
899 views

iptables rule to drop SYN and FIN attacks

From a Trustwave report, we are trying to set our server to block this type of request but after trying several combinations of rules, we can still see the ports. Could anyone give me a hint or the ...
0
votes
1answer
723 views

iptables & nmap on ubuntu

The following are my iptable rules on a ubuntu cloud server: cat /etc/iptables.rules: *filter :INPUT DROP [598:41912] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [456:35354] -A INPUT -i lo -j ...