I tried this solution:
iptables -I OUTPUT -p tcp --dport 2195 -j ACCEPT
/etc/init.d/iptables stop
/etc/init.d/iptables start
but still can't access the port.
If there are more ports that I have to open for APNS let me know.
How about:
iptables -A INPUT -p tcp --dport 2195 -j ACCEPT
service iptables restart
This may help too.
It didn't work for me completely, since my last rule was DROP ALL which basically negated all I added to iptables after.
It might be useful to use the -I switch:
iptables -I INPUT 1 -p tcp --dport 2195 -j ACCEPT
The INPUT 1 - means 1st Input rule instead of appending, to put rule in front of drop all
See my anwser here: https://stackoverflow.com/a/25229943/1472048
For CentOS 7, you should use "firewall-cmd" command like so:
firewall-cmd --add-port=2195/tcp --permanent
iptables is not recommended if you use the firewalld service.
Try the following command, it worked for me:
$ sudo iptables -A INPUT -p tcp --jport 2195 -j ACCEPT
$ sudo /etc/init.d/iptables save
Related
CONTEXT:
I wanted to have a shell script that would block all Inbound/Outbound traffic to my computer, UNLESS I decide I want to use the browser or some other application, in which case I would summon it and only those applications would run.
I have researched previous scripts made by smart individuals (links to sources at the end), as well as invested the time to learn to use iptables myself (still working on this front).
Here is the result of the work done:
RESULTS:
before the shell script is run, a group called internet is created:
sudo groupadd internet
Shell Script:
#!/bin/sh
#only allow apps run from "internet" group to run
# clear previous rules
sudo iptables -F
# accept packets for internet group
sudo iptables -A OUTPUT -p tcp -m owner --gid-owner internet -j ACCEPT
sudo iptables -A OUTPUT -p udp -m owner --gid-owner internet -j ACCEPT
# also allow local connections
sudo iptables -A OUTPUT -p tcp -d 127.0.0.1 -j ACCEPT
sudo iptables -A OUTPUT -p tcp -d 192.168.0.1/24 -j ACCEPT
# reject packets for other users
sudo iptables -A OUTPUT -j REJECT
# same process for IPv6:
sudo ip6tables -A OUTPUT -p tcp -m owner --gid-owner internet -j ACCEPT
sudo ip6tables -A OUTPUT -p udp -m owner --gid-owner internet -j ACCEPT
sudo ip6tables -A OUTPUT -p tcp -d 127.0.0.1 -j ACCEPT
sudo ip6tables -A OUTPUT -p tcp -d 192.168.0.1/24 -j ACCEPT
sudo ip6tables -A OUTPUT -j REJECT
this is the other part of the shell that I'm currently working on and not 100% confident with:
#DROPS ALL INPUT and FORWARD
sudo iptables -A INPUT -j DROP
sudo iptables -A FORWARD -j DROP
#ONLY ACCEPTS INPUT THAT WAS INITIATED BY SOME OUTPUT
sudo iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
#SAME REPEATED FOR IPv6
sudo ip6tables -A INPUT -j DROP
sudo ip6tables -A FORWARD -j DROP
sudo ip6tables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
after the whole script above is executed, the following command would open a terminal that would be part of the internet group, and hence any application (like firefox for instance) that were open by that terminal would have internet access, while all other INPUT/OUTPUT would be stopped
sudo -g internet -s
QUESTION:
Is the previous logic in order? Currently I am working on testing out all the features, by installing network monitoring software (nethogs), testing each line of code and seeing if the result is as expected, BUT at the same time, I only started learning about iptables 2 days ago, so even though the sources of the original code is done by experienced coders, I am not 100% confident in my ability to put it all together to produced the desired result. Thanks to anyone who took the time to read all this and participate in the discussion !!!
sources:
https://plus.google.com/+TobyKurien/posts/YZhZJCZmGgm
https://serverfault.com/questions/429400/iptables-rule-to-allow-all-outbound-locally-originating-traffic
P.S.: Thanks to #dirkt for previously helping me understand a lot of the fundamental concepts of iptables as well as answering some of my questions regarding the source code.
UPDATE:
So after having run the code, there seems to be something wrong. What happens is as follows. I run the shell script:
bash myscript
I get 2 errors as follows:
ip6tables v1.6.0: host/network 127.0.0.1 not found
Try `ip6tables -h' or 'ip6tables --help' for more information.
ip6tables v1.6.0: host/network 198.168.0.1 not found
Try `ip6tables -h' or 'ip6tables --help' for more information.
but everything else ran well, and when doing sudo iptables -L I did confirm all the other rules are in place. AFTER that, I tried the following:
Run firefox by manually double-clicking the icon. The result was as expected, right away I got a Server not found error, which was a good sign
After that I ran the command sudo -g internet -s in the terminal, and then firefox. NOW... when I tried loading a website, it didn't show me Server not found, but it keep loading for a long period of time, very long. This leads me to believe that maybe the output response was sent, BUT the input was being blocked.
If anyone knows why this might be happening, I would love to know your feedback!
I only started learning about iptables 2 days ago, so even though the sources of the original code is done by experienced coders, I am not 100% confident in my ability to put it all together to produced the desired result.
Coincidentally, I'm looking for the same solution around the same time and saw your post. Just sign-up SO, hope this could help you and others. I'm still learning and open to suggestion and advice :)
A few change to the code. I need to open all port to local connections to make it work.
Also changed 192.168.0.1/24 to 192.168.0.0/16. This range allowed wifi/usb tether to be included.
# also allow local connections
#TODO. Use log to see which port are actually needed.
sudo iptables -A OUTPUT -d 127.0.0.1 -j ACCEPT
sudo iptables -A OUTPUT -d 192.168.0.0/16 -j ACCEPT
Is the previous logic in order?
Change the order for/to this code.
#ONLY ACCEPTS INPUT THAT WAS INITIATED BY SOME OUTPUT
sudo iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
#DROPS ALL INPUT and FORWARD
sudo iptables -A INPUT -j DROP
sudo iptables -A FORWARD -j DROP
Also add this code on top of previous code. These are taken from default firewall. Originally it contained specific interface.
sudo iptables -A INPUT -p udp -m udp --dport 53 -j ACCEPT
sudo iptables -A INPUT -p tcp -m tcp --dport 53 -j ACCEPT
sudo iptables -A INPUT -p udp -m udp --dport 67 -j ACCEPT
sudo iptables -A INPUT -p tcp -m tcp --dport 67 -j ACCEPT
I get 2 errors as follows:
ip6tables v1.6.0: host/network 127.0.0.1 not found Try `ip6tables -h' or 'ip6tables --help' for more information.
ip6tables v1.6.0: host/network 198.168.0.1 not found Try `ip6tables -h' or 'ip6tables --help' for more information.
Probably because you are using IP4 address.
Change 127.0.0.1 to ::1/128 and 198.168.0.1 to fe80::/10.
Can't help much about IPv6. I have no idea how it work and I don't think mine using IPv6 at all.
Complete Script:
#!/bin/sh
#only allow apps run from "internet" group to run
# clear previous rules
sudo iptables -F
# accept packets for internet group
sudo iptables -A OUTPUT -p tcp -m owner --gid-owner internet -j ACCEPT
sudo iptables -A OUTPUT -p udp -m owner --gid-owner internet -j ACCEPT
#Some application need more port. Such as ping.
sudo iptables -A OUTPUT -p icmp -m owner --gid-owner internet -j ACCEPT
#Less secure. Open all port.
#sudo iptables -A OUTPUT -m owner --gid-owner internet -j ACCEPT
# also allow local connections
#TODO. Use log to see which port are actually needed.
sudo iptables -A OUTPUT -d 127.0.0.1 -j ACCEPT
sudo iptables -A OUTPUT -d 192.168.0.0/16 -j ACCEPT
# reject packets for other users
sudo iptables -A OUTPUT -j REJECT
#Taken from default rules.
sudo iptables -A INPUT -p udp -m udp --dport 53 -j ACCEPT
sudo iptables -A INPUT -p tcp -m tcp --dport 53 -j ACCEPT
sudo iptables -A INPUT -p udp -m udp --dport 67 -j ACCEPT
sudo iptables -A INPUT -p tcp -m tcp --dport 67 -j ACCEPT
#ONLY ACCEPTS INPUT THAT WAS INITIATED BY SOME OUTPUT
sudo iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
#DROPS ALL INPUT and FORWARD
sudo iptables -A INPUT -j DROP
sudo iptables -A FORWARD -j DROP
#IPv6 Section
# Flush ip6tables too
sudo ip6tables -F
# same process for IPv6:
sudo ip6tables -A OUTPUT -p tcp -m owner --gid-owner internet -j ACCEPT
sudo ip6tables -A OUTPUT -p udp -m owner --gid-owner internet -j ACCEPT
sudo ip6tables -A OUTPUT -d ::1/128 -j ACCEPT
sudo ip6tables -A OUTPUT -d fe80::/10 -j ACCEPT
sudo ip6tables -A OUTPUT -j REJECT
sudo ip6tables -A INPUT -p udp -m udp --dport 53 -j ACCEPT
sudo ip6tables -A INPUT -p tcp -m tcp --dport 53 -j ACCEPT
sudo ip6tables -A INPUT -p udp -m udp --dport 67 -j ACCEPT
sudo ip6tables -A INPUT -p tcp -m tcp --dport 67 -j ACCEPT
sudo ip6tables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
sudo ip6tables -A INPUT -j DROP
sudo ip6tables -A FORWARD -j DROP
In my CentOS 6 i added a IPtables rules like DROP all the policy like
iptables -P INPUT DROP
Then I allow Port NO 22,80,443 with this command,
iptables -A INPUT -i eth0 -p tcp --dport 80 -j ACCEPT
iptables -A INPUT -i eth0 -p tcp --dport 443 -j ACCEPT
iptables -A INPUT -i eth0 -p tcp --dport 22 -j ACCEPT
Now can access SSH with putty. But i can't access Internet. I have to know the exact problem of this.? Please help me.
Ofcourse you cannot access the Internet. You just added a rule that drops all incoming traffic (except for traffic coming in to ports 22, 80 and 443).
When you try to access the internet (if you're using a browser), your machine establishes a connection from
<local IP>:<port1> <----> <remote IP>:80
When the remote server responds to you, it will respond back to the same port1 that you sent the request from (which will NOT be 22, or 80, or 443. It will be a number usually higher than 32768), so it will get dropped by iptables.
Try these rules instead:
iptables -P INPUT DROP
iptables -I INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -i eth0 -p tcp --dport 22 -j ACCEPT
iptables -A INPUT -i eth0 -p tcp --dport 80 -j ACCEPT
iptables -A INPUT -i eth0 -p tcp --dport 443 -j ACCEPT
The second rule tells IP tables to ACCEPT traffic that is coming to us, if it's coming to a port that we used to send outgoing traffic. This will allow you to see the response from the server, which you were dropping.
However, there's still a problem with DNS traffic, since it uses UDP not TCP. You can work around that by changing the first rule to:
iptables -P INPUT -p tcp DROP
so it only drops TCP traffic but not UDP traffic. There may be other ways to work around the DNS problem, depending on what exactly you want to do.
So your final ruleset should look like this:
iptables -P INPUT -p tcp DROP
iptables -I INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -i eth0 -p tcp --dport 22 -j ACCEPT
iptables -A INPUT -i eth0 -p tcp --dport 80 -j ACCEPT
iptables -A INPUT -i eth0 -p tcp --dport 443 -j ACCEPT
As you can image, we need iptables to block the ports we do not need to protect server.
But I need to request some third party resource, and I got confuse on how to do it.
Here are my iptables rules
iptables -F
iptables -A INPUT -p UDP -j ACCEPT
iptables -A INPUT -p tcp --dport 22 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j ACCEPT
iptables -A INPUT -s 110.75.147.65/32 -j ACCEPT
iptables -A INPUT -s localhost -j ACCEPT
iptables -A INPUT -j DROP
And 110.75.147.65/32 is the one of third party servers' IP, I wonder if there are any way to allow all connection started by my server such as curl https://www.google.com/, otherwise I need to add all my third party servers' IP to the iptables rules.
How about
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
i REALLY need some help before my laptop goes through the wall.
I want to run a virtual machine through tor middlebox. I want the entire VM`s connection to go through the tor network. (Im wanting to setup my hidden service and for my needs this will work best)
I started by looking here - http://www.howtoforge.com/how-to-set-up-a-tor-middlebox-routing-all-virtualbox-virtual-machine-traffic-over-the-tor-network
I know this is old but i figured i`d give it a go anyway.
For reference my Host machine is running Ubuntu 13.04 and the VM will be running 12.04LTS. On virtualbox
Well i have tor installed as per the guide, i have gone though the setup steps. But it didnt work. My VM will not connect to the net. I checked ifconfig and i am recieving an ip address, but i cant get a connection to the web to check i am running through tor.
I`ve spent a good few hours on this but i cant get it working, im just at point and click mode now. Looked at so many sites, and almost all of them point back to the original. I have tried tweaking the settings, and looked at numerous forums. But i cant get this working.
If i try using the tor browser bundle, it refuses to start tor, stating the it hasn`t got permission or cant listen on 172.16.0.1:53. tried using vidalia bundle for the tor install but that refuses to find the tor exec (not really an issue)
Here are the settings i am trying to run with...
/etc/network/interfaces
as stated in guide
/etc/dnsmasq.conf
interface=vnet0
listen-address=192.168.1.1
dhcp-range=172.16.0.2,172.16.0.254,1h
/etc/tor/torrc
VirtualAddrNetwork 10.192.0.0/10
AutomapHostsOnResolve 1
TransPort 9040
TransListenAddress 172.16.0.1
TransListenAddress 192.168.1.1
DNSPort 53
DNSListenAddress 172.16.0.1
DNSListenAddress 192.168.1.1
middlebox.sh
#!/bin/sh
# destinations you don't want routed through Tor
NON_TOR="192.168.1.0/24 192.168.0.0/24"
# the UID Tor runs as
TOR_UID="109"
# Tor's TransPort
TRANS_PORT="9040"
# your internal interface
INT_IF="vnet0"
iptables -F
iptables -t nat -F
iptables -t nat -A OUTPUT -o lo -j RETURN
iptables -t nat -A OUTPUT -m owner --uid-owner $TOR_UID -j RETURN
iptables -t nat -A OUTPUT -p udp --dport 53 -j REDIRECT --to-ports 53
for NET in $NON_TOR; do
iptables -t nat -A OUTPUT -d $NET -j RETURN
iptables -t nat -A PREROUTING -i $INT_IF -d $NET -j RETURN
done
iptables -t nat -A OUTPUT -p tcp --syn -j REDIRECT --to-ports $TRANS_PORT
iptables -t nat -A PREROUTING -i $INT_IF -p udp --dport 53 -j REDIRECT --to-ports 53
iptables -A FORWARD -i $INT_IF -p udp -j DROP
iptables -t nat -A PREROUTING -i $INT_IF -p tcp --syn -j REDIRECT --to-ports $TRANS_PORT
iptables -A OUTPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
for NET in $NON_TOR 127.0.0.0/8; do
iptables -A OUTPUT -d $NET -j ACCEPT
done
iptables -A OUTPUT -m owner --uid-owner $TOR_UID -j ACCEPT
iptables -A OUTPUT -j REJECT
Does this article help you? http://www.mike-warren.com/articles/routing-vm-traffic-through-tor.html
The short version is:
host runs a tun/tap device
host runs a VDE switch (which puts packets from the VM into the tap device)
host has iptables NAT rules to shovel tap device traffic into Tor
host runs Tor as transparent proxy
VM has static IP, connected to VDE switch
Instead of all that, you could run TAILS instead. https://tails.boum.org/
Consider running tails as vm guest.
Use a vm snapshot to avoid booting from tails live dvd (iso)
I have an application listening at port 27015. I want to allow all ips with client port 27005 and drop the rest. How do I go about this ?
This page shows some good examples of iptables.
http://www.cyberciti.biz/tips/linux-iptables-how-to-specify-a-range-of-ip-addresses-or-ports.html
So, something like this should do it:
iptables -A INPUT -p tcp --sport 27005 --dport 27015 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A INPUT -j DROP
Little late but here is what I would do
iptables -A INPUT -p tcp --dport 27005 -j ACCEPT
iptables -A INPUT -j DROP
service iptables save
service iptables restart