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Iptables rules make communication so slow

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linux-howto

http://serverfault.com – 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. What makes communication so slow? -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT -A INPUT -p tcp -m tcp --dport 22 -j ACCEPT -A INPUT -p esp -j ACCEPT -A INPUT -i ppp+ -j ACCEPT -A INPUT -p udp -m udp --dport 500 -j ACCEPT -A INPUT -p udp -m udp --dport 4500 -j ACCEPT -A INPUT -p udp -m udp --dport 1701 -j ACCEPT -A INPUT -i lo -j ACCEPT -A INPUT -i lo -m state --state NEW,RELATED,ESTABLISH (HowTos)

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Submitted by dayu on 10/10/2012

Stories similar to Iptables rules make communication so slow

I've setup IPTables with the following script...

I have the following rule,which i believe will restrict icmp packets to 1/s.

open Ports in IP tables 3 years 16 weeks ago

Hi I would like to open some port from IN to OUT

pop3,smtp. whenever i tried to add some rules to existing iptables it gives me an error Applying iptables firewall rules: iptables-restore: line 21 failed

I am using the Cent OS 5.3

how do i open the ports?

INPUT ACCEPT [0:0] :FORWARD ACCEPT [0:0]

# Generated by iptables-save v1.4.8 on Sat Apr 27 19:02:58 2013 *filter :INPUT ACCEPT [812:348051] :FORWARD ACCEPT [154:112203] :OUTPUT ACCEPT [1781:859968] -A INPUT -s 192.168.0.50/32 -i eth0 -p tcp -m tcp --dport 3128 -j ACCEPT -A INPUT -s 192.168.0.50/32 -i eth0 -p tcp -m tcp --dport 22 -j ACCEPT -A INPUT -s 192.168.0.50/32 -i eth0 -p tcp -m tcp --dport 80 -j ACCEPT -A INPUT -s 192.168.0.60/32

[ubuntu] IPTables problems 26 weeks 5 days ago

Hi

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

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'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

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

Chrony and iptables 46 weeks 1 day ago

Hi

This is my iptables configuration (only allow chronyd for NTP):

*filter :INPUT DROP [0:0] :FORWARD DROP [0:0] :OUTPUT DROP [0:0] -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT -A INPUT -i lo -j ACCEPT -A OUTPUT -o lo -j ACCEPT -A OUTPUT -p tcp --dport 53 -m owner --uid-owner chrony -j ACCEPT -A OUTPUT -p udp --dport 53 -m owner --uid-owner chrony -j ACCEPT -A OUTPUT -p