Networking :: Only Allow OpenVPN Connections With IPtables ?
May 23, 2011
I'd like to configure IPtables to make sure I can only access the internet through an openvpn connection (so when the connection is down I have no way to access the internet but to connect to the vpn again).
I know how to do this with Firestarter (restrictive outgoing policy and I only allow the vpn server IPs) but Firestarter seems to be stupid : for some reason eth0 was changed to eth1 and Firestarter can't work properly anymore, even though that probably can be fixed with Firestarter I'm no more interested in this program and I'd better like to know how to apply the same policy using IPtables.
I've tried a few things already but it failed each time ... how can I effectively allow my computer to connect to the VPN while everything else is blocked ?
I have set up OpenVPN for my connection. I'm using this to connect to the internet from different locations using tunnelling.
Right now I have a few IP's : on eth0 I have IP from my ISP, on eth0:1 I have my own IP.I set up MASQUERADE to eth0 - but in this case when I try to access my restricted resources IP address from ISP is visible. What I want is to use my own IP address from eth0:1 - could somebody help me to build good working redirect entry for that? I want to redirect all connections to that IP assigned on eth0:1... - just to access Internet using my IP.
I'm trying to set up an openVPN server for a small office. I've gotten the server running, and configured keys, and been able to connect to the server. The trouble is that once I connect with my windows machine to the server, I am unable to bridge through to the www. I have combed through so many settings and tutorials, and I am confused as to how to set up the interfaces configuration file. Here's a sample of my routing table:
Code: Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 10.8.0.2 * 255.255.255.255 UH 0 0 0 tun0 XXX.XXX.XXX.0 * 255.255.255.128 U 0 0 0 eth0 10.8.0.0 10.8.0.2 255.255.255.0 UG 0 0 0 tun0 default XXX.XXX.XXX.1 0.0.0.0 UG 100 0 0 eth0
How should I be configuring this so that when I'm in the VPN I can get through to the internet?
my problem is following: I'm running a bridged OpenVPN on my Debian. If the service is running, everything works fine: local and Internet, ftp, mailing from in and outside etc. But, when stopping OpenVPN, sending mails from inside (LAN) fails: I cannot reach smtp (postfix) listening on port 465. And even reaching mailboxes using IMAP gets horribly slow eg. in Thunderbird. Here is my firewall.sh script.
Quote:
#!/bin/sh echo " IPTABLES FIREWALL inicializalasa - szures" # Enter the designation for the Internal Interface's INTIF="eth0"
I want to find out which server/service a streaming box connects to and maybe also take a look at some packets. The box connects to the Internet via a Linux gateway running Debian I have root access to. I have some basic knowledge about iptables, tcpdump, netstat etc. but couldn't yet figure out how to get this info.
My first approach was with netstat, but this traffic seems not to be visible (which somehow makes sense to me). My next guess was that with iptables it should be possible to log this connections, however I couldn't yet figure out how to.
So far this works perfectly. What I want to do now is to add another rule that only nats the machine in case it is NOT accessing subnet 1.
In other words, when this machine accesses any other machine in subnet 1, it should show up as 10.1.0.10. Whenever it accesses subnet 2 of anything else, it should appear as 172.16.0.10.
I'm running Ubuntu 10.04 LTS as a VM in Hyper-V, and accessing it via VNC with a machine in the same broadcast domain. I'm using OpenVPN to connect to XeroBank. I have instructions for configuring iptables to permit establishing and using the XeroBank connection, while blocking all other traffic on eth0. I've followed them successfully. I need to also permit the VNC connection, and haven't managed that. FWIW, the VM is at 192.168.111.12::5900 and the workstation is 192.168.111.2.
The attachment to this post lists the recommended contents for each Shorewall file. Which files need changed, and what do I add to each?
i have some problems with configuring openvpn tunnel connection to my openvpn server. I'm using static-key tcp connection. Network manager always said to me that connection could not be established. Also, when i try to run openvpn from terminal, i got some strange permissions problem:
Code:
openvpn --config config.ovpn Mon Apr 5 15:48:37 2010 OpenVPN 2.1_rc19 i486-pc-linux-gnu [SSL] [LZO2] [EPOLL] [PKCS11] built on Oct 13 2009 Mon Apr 5 15:48:37 2010 NOTE: OpenVPN 2.1 requires '--script-security 2' or higher to call user-defined scripts or executables Mon Apr 5 15:48:37 2010 /usr/sbin/openvpn-vulnkey -q moj.key
I managed to set up an openvpn server, ip-forwarding and a nat iptable rule for that.
Almost everything works as expected, but my problem is:
Smartphone -> VPN -> Internet ==> works (by ip and hostname) Smartphone -> VPN -> machine in my local network by IP ==> works Smartphone -> VPN -> machine in my local network by its hostname => DOES NOT WORK Machine w/ VPN server -> ping to machine in local network by ip or hostname => works
So, i wonder why i cant access a local machine through the vpn by its hostname. I guess I'm missing a forwarding rule??
iptables dump: # Generated by iptables-save v1.4.21 on Sun Feb 7 20:56:52 2016 *nat :PREROUTING ACCEPT [786:59064] :INPUT ACCEPT [728:53047] :OUTPUT ACCEPT [19:1487] :POSTROUTING ACCEPT [20:1576] -A POSTROUTING -s 10.8.0.0/24 -j MASQUERADE COMMIT # Completed on Sun Feb 7 20:56:52 2016
I have tried to configure my iptables to allow only HTTPS connections to the internet. Unfortunately, I didn't get that to work. I configured it like this:
Quote:
iptables -P INPUT DROP iptables -P OUTPUT DROP iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT iptables -A OUTPUT -t filter -p tcp --dport 53 -j ACCEPT iptables -A OUTPUT -t filter -p udp --dport 53 -j ACCEPT
[Code]....
Of course I am only trying to access websites via HTTPS Still, I was wondering if HTTPS somehow under the hood requires the HTTP port to be open or if my rules are in some other way wrong.
I'm having problems with hackers from across the globe trying to get into our servers. Why? i have no clue. nothing of value in my servers worth getting.
Right now my service only does business with USA. So I'm trying to find a way to block all Non USA traffic. I called my hosting provider and they are unable to help. Said it was up to me to do this.
Well I've already taken care of the TCP Wrappers. by spawning a small C program i made that uses MaxMind's GeoIP system. to automatically deny access. Now i need to do something about all the other network connections that come in to services that do not use the TCP wrappers.
So i was wondering if IPTABLES have a way to spawn a sub proccess like TCP wrappers or if there was any other firewall software out there for linux that would let me achieve my goal.
I'd like high-availability feature to firewall (iptables) and openvpn service I'm running at my job. Mi project is two firewall boxes in a active/pasive configuration. And if it's possible sync connections' states. I started reading on heartbeat and I'd like to hear some advices and take away some doubts: For the config I'm planning heartbeat service is enough or it would require a CRM service such as pacemaker.
I have a server that I can only access via SSH (it's located far away) and I would like to secure it by blocking all ports except the ones that I need (which are HTTP and SSH). I still want to be able to make outgoing connections to enable software updates and other things.This is my iptables -L -n :
Code: Chain INPUT (policy ACCEPT) target prot opt source destination ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED DROP tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpts:1:21 DROP tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpts:23:79 DROP tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpts:81:65535 code....
In my opinion, this should block all incoming packets except the ones on port 80 and 22, but allow responses to outgoing connections. But a wget http://google.com does not work, it can't establish the connection.
Maybe this is not the best style for iptables rules, but I want to be absolutely sure to not accidently lock myself out from SSH, so I chose not to configure a "block-everything rule".
Does this configuration not enable incoming packets from connections initiated from inside?
have a problem with my network-manager in ubuntu 10.10.when I dial one of my vpn connections, my other vpn connections be disabled and I can't use them!I tried to restart network-manager and gnome-panel, but it does't seem to solve this problem.
I want to configure a VPN over the Internet.I installed the 'openvpn' package, generated the key file, transfered it by a secure way to the client, and setted up the configuration file.
So, in that configuration file I input the IP addresses of the tunneled interfaces. Both IPs are static in the tunnel.
Then, I've heard somewhere that I can assign a dynamic configuration IP for the client. I do this registering a range.
Well, when I tried to change static IP to dynamic IP (changing '192.168.0.2' to '192.168.0.0/24') in the configuration file, the OpenVPN didn't work.
Obviously I don't know what I'm doing, and I really, don't believe that simply changing the IP will make it work, but I tried.
I hope I explained my problem as well.
My configuration file:
# OpenVPN Server Configuration File dev tun 0 ifconfig 192.168.0.1 192.168.0.2 cd /etc/openvpn secret key_file
In client I execute the 'openvpn' without the '--daemon' parameter.Then I want that my client uses a IP in a range (192.168.0.0/24, for example), instead of a static IP (192.168.0.2).I also thought to use a DHCP server, but I'm not sure that will work.
I have been trying to set up openVPN on a Virtual Machine running Ubuntu 10.04 with the eventual intention of having a closed VPN in the workspace I'm at, and a bridged internet connection out through the server.My initial process/instinct was to go through Webmin. After a fair bit of tooling around making eys/certificates, I was able to get a response (and that's all it was, really) from my windows machine accessing the VPN server. However, in my attempt to bridge the network, I have lost all internet/networking capabilities from the server.Fortunately I am able to access the server directly from the hardware underneath (i.e. I don't need to SSH in or anything), and so I've been attempting to restore the server's networking back to default. I have returned the /etc/network/interfaces file to it's original state (just the loop, and an eth0 on dhcp) and restarted the networking. A check with ifconfig returns what seems to be a working eth0, and the loop (noting else) however I am unable to ping any outside server. When I do, I am given the message:From XXX.XXX.XXX.XXX icmp_seq=1 Destination Host Unreachable(where of course XXX is my IP address).nother VM on the server is able to access the internet just fine, so it's not the overall server hardware...I guess at this point I'm just trying to take steps back,
Is it fair to say that connLimit and hashlimit are very similiar on Linux i.e. while hashlimit caters to limits for groups of ports, they both set the connection rate limit per host? How in IPTables, do I configure a policy that limits connections on a port that encapsulates the total sum of all connections from all hosts? i.e. I do not want to allow more than 6000conn/minute for port range that is the sum of all connecting hosts?
I recently installed Fedora 15 now, and during installation I set the internet connection manually, then did update and after reboot, the internet connection settings have been removed. Now I can not set because the network connection to the Internet Connection is inactive. I mention that before the update was functional internet connection.
i've set up an openvpn server (with dhcp running on it) and i have to create compatible clients.the problem is how to get an ip by dhcp.with ubuntu i made a script like this
/sbin/ifconfig tap0 up /sbin/dhclient -e tap0
and everything works fine:tap0 goes up and then start a dhcp request to the server on tap0with fedora there is a nice problem i've noticed that is impossible to run dhclient later on a new interface because i receive this error "dhclient is already running".the tap0 goes up normally but i receive this error when i attempt to get an ip.is there a simple way to get an ip?if i try to kill or restart dhclient when the vpn tunnel is up,all'interfaces lost theirs ip and network goes down crashing my vpn...
Is there anyway you can configure either OpenVPN client or the system to allow connections using OpenVPN to be made to computers on the OpenVPN network using their alias rather than their IP address. This may sound blasphemous but you can in Windows. That is if the VPN network is say 10.x.0.x I could connect to Comp4 or Comp2 using Comp4 or Comp2 not 10.x.0. 4 or 10.x.0.2 or whatever IP is allocated by the OpenVPN server. If the OpenVPN server has not been restarted then it will usually allocate the same IP every time the same client connects.
I have access to a VPN I use when having confidential instant messaging sessions. For the purposes of my work, essentially.I'm a command line kind of guy, and like to use Finch (the shell version of Pidgin) for those.However, when I turn on my OpenVPN connection it routes all traffic through the VPN. Web-browsing, IMing, and I can no longer access other machines on my home network.Can I set OpenVPN to only route traffic I ask through that connection (either by port number or application, or some way I haven't thought of), while other traffic flows through my usual home network?Some kind of local proxy perhaps? Or a dd-wrt box set up as a proxy, connected to OpenVPN?I've played around with the GUI environment too (I have a basic GUI I sometimes use on my main machine) and have installed the full desktop 10.10 on a second machine just to see if I can work it out.
My boss gave me the task (on a very tiny budget) of wanting to connect our remote offices to our network. Solution I came up with is Site-to-Site VPN.
I want to use OpenVPN on the Linksys Routers (again very tiny budget) and have them connect to our Cisco ASA5505 Firewall, but I am running into major problems.
Question is, even though they both use IPSec SSL are they compatible? If not, is there a work sround?
I have installed OpenVPN to use it as an internet gateway butcan't get it to work.OpenVPN installed without any problem. The client can also connect and ping the server but there is no internet traffic.I think it is because of a wrong gateway address which the client gets but I'm not sure. server IP address is 10.8.0.1 and the client can ping this IP but it's default gateway is always 10.8.0.5 which is not accessible from the client.This is my server.conf:
