Ubuntu :: Remove All Iptable Rules And Chains?
Aug 6, 2010How would you remove all iptable rules and chains?
View 2 RepliesHow would you remove all iptable rules and chains?
View 2 RepliesI've read the instruction about setting up the iptables rules to filter all port except HTTP, SSH, FTP. I require first remove all default iptables rules and set default rules to all chains as DROP:
# Set default-deny policies for all three default chains
$IPTABLES -P INPUT DROP
$IPTABLES -P FORWARD DROP
$IPTABLES -P OUTPUT DROP
Then allow only some ports:
#Accept inbound packets that are part of previously-OK'ed sessions
$IPTABLES -A INPUT -j ACCEPT -m state --state ESTABLISHED,RELATED
# Accept inbound packets which initiate SSH sessions
$IPTABLES -A INPUT -p tcp -j ACCEPT --dport 22 -m state --state NEW
# Accept inbound packets which initiate FTP sessions
$IPTABLES -A INPUT -p tcp -j ACCEPT --dport 21 -m state --state NEW
# Accept inbound packets which initiate HTTP sessions
$IPTABLES -A INPUT -p tcp -j ACCEPT --dport 80 -m state --state NEW
# Log anything not accepted above $IPTABLES -A INPUT -j LOG --log-prefix "Dropped by default:"
But I hired a VPS from other country so the only mean I can manage it is via SSH. If I setup the default rule to DROP first, I afraid that I can no longer connect via SSH to tell iptables allow SSH
So my question is:
- Does the IP tables take effect immediately after I input a rule?
- Is there any mean to run this as a batch job (create a script and run all these rules one time).
- My VPS has a web control panel which have a terminal via web. Is this a native terminal or just a connection via port 80 or 22?
I want to simplify some of my rules, so I want to create rules for certain services like xmpp, web, etc. since some of them use multiple ports, and I toggle them on/off a lot. Can I simply put the jump to rule clauses in the Input chain, and once the sub chains run, does it return to the input chain after the jump to rule clause? I want to do this so I don't have a ton of rules in the input chain. I think that if I simply make a list of all the rules to jump to in the input chain, it will work itself through all of them until it finds a matching filter in one of them correct?
View 9 Replies View RelatedExplain the following iptable rules for me?
I understand 1 and 2, 1 creates the new syn_flood chain and 2 redirects all SYN requests to the new syn_flood chain.
I'm having trouble understanding 3 and 4. can someone explain to me in laymen terms the --limit 1/s and --limit-burst 3?
I've configured iptables to act as a stateful firewall, but instead of simply rejecting packets I'd like to waste a potenial hackers time by droping any packet that would otherwise be returned. Are my rules sufficient or have I somehow opened myself up to an attacker by trying to write these rules myself?
View 3 Replies View RelatedI have a caching dns and SNMP ( MRTG ) both on the same server how can I permit dns and snmp traffic in INPUT chain?? I have tried the following:
iptables -A INPUT -p udp --sport 1024:65535 --dport 53 -j ACCEPT
iptables -A INPUT -p udp --sport 53 --dport 1024:65535 -j ACCEPT
iptables -A INPUT -p udp --sport 1024:65535 --dport 161:162 -j ACCEPT
iptables -A INPUT -p udp --sport 161:162 --dport 1024:65535 -j ACCEPT
I recently set up a ftp server in my house running a dyndns service so I can get to it from the outside. I called my isp to get some help in setting up the router to forward port 21 from the outside to that box, and in short we had some problems. Long story short, they ended up bypassing the router itself, and now the line running to the box is its own fixed external ip. Naturally I want a pretty darn good iptables setup for this. The box runs proftpd and so far my iptables only accepts local loopback and port-21. (I left port 80 closed as its only purpose is to be a standalone ftp server) But I know there must be a safer rule for port 21, as right now its just wide open. Anyone have any ideas on how to make this a bit safer? Also would that command be fine for any of the linux machines im connecting to it from the outside too?
View 3 Replies View RelatedI don't know if FC15 has the iptable rules like the ones shown below by default or not but I wanted a second opinion about the safety they provide. Why is icmp accepted (INPUT rule 1) from/to all ip? and is it better to remove this rule? When the protocol is all (INPUT rule 2), does it mean from ip layer and above?? and is it required/safe to have this rule? The 3rd rule is to allow tcp-port 22 connections (ssh) to/from all ip. I think this is correctly set and required. The 4th rule in INPUT table rejects pings with the icmp-host-prohibited message; which I don't think is the best solution. Instead it can be set to silently drop icmp packets. Then, the FORWARD table uses reject instead of silent drop for forwarding icmp ping packets.
Code:
what do you think about the new rules and their order?
I'm trying to set up a firewall at the moment that allows access to my custom SSH port from only my friend's url (they have a static url but dynamic IP). I find iptables a bit of a nightmare and was hoping to use UFW for most of my day to day firewall maintenance and just make a few extra iptable rules to cover exceptional circumstances like this. Fortunately it seems UFW allows this with /etc/ufw/before.rules and /etc/ufw/after.rules. So at the moment I'm just trying to get the basic iptables rules right. As I say I'm not very good with iptables, does this look right?
Code:
## Drop Default SSH port access With Logging
iptables -N SSH_DEFAULT
iptables -A INPUT -p tcp --dport 22 -m state --state NEW -j SSH_DEFAULT
[code].....
I am having a Xen server xend daemon is taking care of giving interface names like vif1.0 or vif0.2 to the connected guest operating systems on it.I can not save the current IPTABLE rules since upon reboot the xend daemon gives different names to virtual ethernet interfaces i.e. vif1.0 or vif3.0 or vif9.0 like that.I have some rules that I want to be active upon subsequent reboots and not all.Say for example an SSH to external server at port 8000 should forward the request to a machine on LAN.Which I have done by port forwarding from IPTABLES.So I need to save some rules.I was thinking to make a script which on reboot activates those rules.
I am not clear on where to do that.I came across internet and found /etc/network/if-up.d/I am not clear with this directory my question is if I make a scrip which has IPTABLE rules as I want and save it in above folder will it work. I am not clear with what is /etc/network/if-up.dfor.Suppose my logic is wrong then how should I go for it.Also I want to know does a protocol uses two port to make a connection.I have forgotten that thing,i.e if I run an SMTP or ssh then do they use port 22 and 23 both in case of ssh or 25 and 26 both for SMTP like that or just specifying the rules for one port will be enough.I tested these rules in a secure environment where i had disabled firewall and ssh forwarding on router worked well
Is there a way to check older iptable rules that were loaded? I accidentally overwrote my iptables and that has killed internet access to all computers in the intranet. I must have accidentally deleted some line in the iptable rules and cannot figure how to get it back to how it was. I am using Debian 5.05 by the way.
View 1 Replies View Relatedwrote a network emulator program in c programming. It can run for ubuntu terminal with good performance.But i have to make it for web-based user configuration. So i had setup apache web server and write this program in cgi script and try to execute this program from web page.This program must be run in root privilege($sudo -s) and add the iptables rules such as (#iptables -A OUTPUT -j QUEUE). So my question is how to add iptables rules in my cgi scripts? How to set the superuser(root privilege) permission to access my program through web server?
View 2 Replies View RelatedI just installed ufw and made some rules :-
Code: Select all$ sudo ufw enable
$ sudo ufw default deny
$ sudo ufw allow 80,443/tcp
Now this gives the following :-
Code: Select allRule added
Rule added (v6)
Now is there anyway to tell it to NOT add the v6 rules (of course over time v6 will become the new standard and I'll have to upgrade my router and all) but till my ISP doesn't I just want to make it easy for myself.
I could install gufw and just take that rule out but wanted to know if there was a way to do that via CLI .
I should create a sqeeze image and install it on other computers.Udev should detect network card (NIC) module and load it automatically at startup.How I understand /lib/udev/rules.d/75-persistent-net-generator.rules runs when udev starts, then writes to /etc/udev/rules.d/70-persistent-net.rules.The problem is, udev searches for this NIC on other hardware and the network cannot start.I can solve this problem easily using a startup script to delete /etc/udev/rules.d/70-persistent-net.rules file.
View 2 Replies View RelatedI've created live squeeze usb-hdd and if I boot first time the udev system writes the MAC address of the network interfaces into /etc/udev/rules.d/70-persistent-net.rules.Because I use full persistence, the file is there on the next boot and I don't get network running automatically on other computers. My problem is, howto remove 70-persistent-net.rules every time during the startup?
View 5 Replies View RelatedI need to create filename 70-android.rules in the directory /etc/udev/rules.d/I have Adm privileges in my user account properties, but when I use sudo to create this file the Ubuntu OS does not allow me the privilege... I am running Ubuntu 10.04 LTS and here's the Terminal output below:daddy@gatomon-laptop:/etc/udev/rules.d$ sudo cat > 70-android.rulesbash: 70-android.rules: Permission denieddaddy@gatomon-laptop:/etc/udev$ ls -ltotal 8drwxr-xr-x 2 root root 4096 2011-03-16 18:03 rules.d-rw-r--r-- 1 root root 218 2010-04-19 04:30 udev.conf
View 2 Replies View Relatedi heard many times the words tool chain , cross platform compiling , cross platform building etc ...
i can use the tool chain for All Linux OS ...?
just wanna ask how many firewall chains are supported by kernel? and what are there..?
View 1 Replies View RelatedIs it possible to only view certain chains and more specifically certain chain policies with options when doing: iptables -L..I would like for example view FORWARD ACCEPT rules instead of waiting for all of the drop rules to load when viewing a firewalled iptables.
View 1 Replies View RelatedWhat commands do you use to set the INPUT, OUTPUT, and FORWARD chains in iptables to ACCEPT?
View 5 Replies View RelatedI need assistance with my Snort Installation. I used Bodhi Zazen's Network Intrusion Detection System post and found it easier than the previous time I had done it. I am currently running Ubuntu 10.04 server and Snort 2.8.6.1 with BASE 1.4.5. I followed Bodhi Zazen's instructions and when I tested snort it ended with a Fatal Error due to ERROR: /etc/snort/rules/exploit.rules(264) => 'fast_pattern' does not take an argument
Fatal Error, Quitting.. Here is the entire output once I ran the test command: snort -c /etc/snort/snort.con -T Running in Test mode
[Code]...
I need help creating an iptable rule. The iptables are installed on my router. My router also connects to a "hide my a**" vpn account
at 79.142.65.5:443 The goal is to somehow force the traffic to go through the vpn, because what sometimes happens is, the vpn connection drops (for what ever reason) and my real ip becomes exposed. Basically, I want to block "myself" from accessing the Internet when not connected to the vpn because of privacy concerns.
Below is my iptables. It has the 3 default chains and it also has many custom user chains. I need to know what kind of a rule to add, What interface to apply it to (lo,tun0,br-lan,eth1) and the correct chain to insert into.For example, you could tell me something like:
Quote:
FORWARD chain, change rule 1 to
iptables -R FORWARD 1 -j zone_wan_MSSFIX -p tcp --destination-port 443 -i eth1
Obviously, That was just a guess, I need someone that knows iptables to help me.
Code:
Chain INPUT (Policy: ACCEPT)
Rule # Traffic Target Prot In Out Source Destination Options
Rule 1 72.95 KB DROP all * * 0.0.0.0/0 0.0.0.0/0 state INVALID
Rule 2 1.11 GB ACCEPT all * * 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
[code].....
In my new Centos i am not able to add iptable rule. iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 3128bash: iptables: command not foundI am getting this error. I use this rule to forward ports to squid.
View 5 Replies View RelatedI have installed squid as my proxy server in ubuntu 10.04 standalone system..Why i have installed squid in standalone sytem is, my friends used to access my system to browse sites and download files..So i have installed squid to block porn sites and downloads..But they simply bypass the proxy by disabling it..I know there is some way to force all browsers to go through proxy using iptables..But how to acheive it..? Is the below command suits my need..?If not what modification should i do..?
Code:
sudo iptables -t nat -A OUTPUT -p tcp --dport 80 -j REDIRECT --to-port 3128
I have a server that is on a high port number, and people want it on port 80. For root exploit issues people say the server can not run as root. So to solve things I want to redirect port 80 to a high port number, say 12345 on the machine. This has been discussed all over the web, so I find I need to do this:
/sbin/iptables -t nat -A PREROUTING -p tcp -d 123.45.67.89 --dport 80 -j REDIRECT --to-ports 12345
/sbin/iptables-save > /etc/sysconfig/iptables
And I do this, an voila things work for the whole world. All machines in the world can see the server on port 80 on the machine.Except, on the machine itself. On the machine 123.45.67.89, I try to get to the server on 123.45.67.89:80, I get a can't connect error. On the machine if I try 123.45.67.89:12345 I can connect.What am I doing wrong here? I don't want localhost network really, I want the ip address and port, but I want the forwarding to work on the local machine. But it doesn't...
I'm looking for a programmatic way to run the equivalent of the below statement using SuSEfirewall2 and make it persistent:
iptables -t nat -A PREROUTING -s 192.168.1.4/32 -p udp --dport 514 -j REDIRECT --to-ports 51414
Yes I know I can add it to FW_REDIRECT in the config, but I really need to handle this on the CLI at run time (which the above statement does do), however... is there an iptables-save equivalent in SuSEfirewall2?
i'd like to know how many rule can manage iptable. I'm asking that because i'd to drop all traffric from my localnet to porn site. I've a database of porn site witch contain about 900 000 domains. I know there are solutions like squidguard. But for my linux box i'd to use iptable to prevent users access to porn site and other blacklist site.
View 1 Replies View RelatedHow to open port at iptable?
My box is centos 5.4.
I wanto to open UDP 177 and TCP 6000~60010.
I can connect my box through putty now.
Is it possible to block a subdomain or a one lower level directory URL access from other hosts or network ? I have a site running on my server and i want to block the particular directory under the domain, with the exception of loopback access? I mean the directory must be accessible from loopback/localhost.
[url] on port 10016(expect loopback)
[url] on port 10016 (expect loopback)
Code:
I try to log all my iptable logs to mysql instead just a logfile. The setup is as followed:
[Code].....
[red]Problem[/red] rsyslog logs everything correct, except it does not log to db, it logs to /var/log/messages. As I am brand new to the whole Linux experience, I don't get it. My /etc/rsyslog.conf is setup with $ModLoad onmysql.