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Iptables blocks outgoing HTTP connection

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linux-howto

http://serverfault.com – I've setup IPTables with the following script... however, I cannot get outgoing HTTP queries to work (I've tried using lynx & curl). Background - server is hosted remotely (and I'm connecting via SSH). Your help will be greatly appreciated... Here's my iptables setup: iptables -P INPUT ACCEPT iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT iptables -A INPUT -p tcp --dport 22 -j ACCEPT # ssh iptables -A INPUT -p tcp --dport 80 -j ACCEPT # http iptables -A INPUT -p tcp --dport 443 -j ACCEPT # https iptables -A INPUT -p tcp --sport 80 -j ACCEPT iptables -A INPUT -p tcp (HowTos)

xskl's picture
Submitted by xskl on 10/29/2012

Stories similar to Iptables blocks outgoing HTTP connection

I'd like to allow mail through iptables and DROP policy but this script doesn't work what it is wrong here:

## FLUSH de reglas iptables -F

iptables -X

iptables -Z

iptables -t nat -F

## policy iptables -P INPUT DROP

iptables -P OUTPUT ACCEPT

iptables -P FORWARD DROP

# localhost iptables -A INPUT -i lo -j ACCEPT

# Allow my ip iptables -A INPUT -s MY_IP -j ACCEPT

# 80 port iptables -A I

I have sendmail installed on Ubuntu 10.04 solely for the use of the php mail() function.

[ubuntu] IPTables problems 30 weeks 5 days ago

Hi

I'm having some problems with my VPS running Ubuntu Server 11.04 x64.

I am trying to configure iptables for ubuntu 10.04 and I have a problem with iptables -L lagging on rows where the destination or source address is not localhost or anywhere.

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 10.1.0.0/20 --dport 22 -j ACCEPT

iptables -P INPUT ACCEPT iptables -P FORWARD DROP iptables -P OUTPUT ACCEPT

iptables -A INPUT -i lo -j ACCEPT iptables -A INPUT -m state --state ESTABLISHED,RELATED -j AC

When I have send a request to an application running on a machine which following firewall rules are applied, it waits so long. When I have deactivated the iptables rule, it responses immediately.

I used an online tool to create an iptables firewall. Basically I just need port 22 and 1194 open to the outside world. But I noticed this bash script has input, forward and output chains as accept by default. Is it blocking all traffic but those two ports? Thanks.

I am running a server which needs UDP ports 1000:11000 opened, as well as TCP 10011 and 30033 open to function.

I have a set of iptables rules set to allow SSH and those ports, and intentionally left out 2010 as I am getting attacked on that port. The server does not block the incoming IP even when told to do so.

How to allow outgoing trafic only for http and ssh?

i've tried:

iptables -A OUTPUT -p tcp --dport ssh -j ACCEPT iptables -A OUTPUT -p tcp --dport http -j ACCEPT

but as soon as i add

iptables -A OUTPUT -j DROP

nothing works, it blocks everything.