openvpn...Please help - UK Web Hosting

**ametovic** · #1 (**permalink**) 30-06-2009, 08:41

Hi all,

my first post here, I am hoping that someone can help me

I have been trying to setup openvpn for some time. few weeks on and off to be precise.

I followed couple of guides and managed to establish a connection from a remote computer (XP and Apple os x 10.5.7) to VPS via openvpn.

I cannot send web traffic from remote machine through openVPN.

this is my server.conf file

PHP Code:


			
#################################################

# Sample OpenVPN 2.0 config file for            #

# multi-client server.                          #

#                                               #

# This file is for the server side              #

# of a many-clients <-> one-server              #

# OpenVPN configuration.                        #

#                                               #

# OpenVPN also supports                         #

# single-machine <-> single-machine             #

# configurations (See the Examples page         #

# on the web site for more info).               #

#                                               #

# This config should work on Windows            #

# or Linux/BSD systems.  Remember on            #

# Windows to quote pathnames and use            #

# double backslashes, e.g.:                     #

# "C:\\Program Files\\OpenVPN\\config\\foo.key" #

#                                               #

# Comments are preceded with '#' or ';'         #

#################################################



# Which local IP address should OpenVPN

# listen on? (optional)

;local a.b.c.d



# Which TCP/UDP port should OpenVPN listen on?

# If you want to run multiple OpenVPN instances

# on the same machine, use a different port

# number for each one.  You will need to

# open up this port on your firewall.

port 11194



# TCP or UDP server?

;proto tcp

proto udp



# "dev tun" will create a routed IP tunnel,

# "dev tap" will create an ethernet tunnel.

# Use "dev tap0" if you are ethernet bridging

# and have precreated a tap0 virtual interface

# and bridged it with your ethernet interface.

# If you want to control access policies

# over the VPN, you must create firewall

# rules for the the TUN/TAP interface.

# On non-Windows systems, you can give

# an explicit unit number, such as tun0.

# On Windows, use "dev-node" for this.

# On most systems, the VPN will not function

# unless you partially or fully disable

# the firewall for the TUN/TAP interface.

#dev tap

dev tun



# Windows needs the TAP-Win32 adapter name

# from the Network Connections panel if you

# have more than one.  On XP SP2 or higher,

# you may need to selectively disable the

# Windows firewall for the TAP adapter.

# Non-Windows systems usually don't need this.

;dev-node MyTap



# SSL/TLS root certificate (ca), certificate

# (cert), and private key (key).  Each client

# and the server must have their own cert and

# key file.  The server and all clients will

# use the same ca file.

#

# See the "easy-rsa" directory for a series

# of scripts for generating RSA certificates

# and private keys.  Remember to use

# a unique Common Name for the server

# and each of the client certificates.

#

# Any X509 key management system can be used.

# OpenVPN can also use a PKCS #12 formatted key file

# (see "pkcs12" directive in man page).

ca /etc/openvpn/keys/ca.crt

cert /etc/openvpn/keys/server.crt

key /etc/openvpn/keys/server.key  # This file should be kept secret



# Diffie hellman parameters.

# Generate your own with:

#   openssl dhparam -out dh1024.pem 1024

# Substitute 2048 for 1024 if you are using

# 2048 bit keys. 

dh /etc/openvpn/keys/dh1024.pem



# Configure server mode and supply a VPN subnet

# for OpenVPN to draw client addresses from.

# The server will take 10.8.0.1 for itself,

# the rest will be made available to clients.

# Each client will be able to reach the server

# on 10.8.0.1. Comment this line out if you are

# ethernet bridging. See the man page for more info.

server 10.7.0.0 255.255.255.0



# Maintain a record of client <-> virtual IP address

# associations in this file.  If OpenVPN goes down or

# is restarted, reconnecting clients can be assigned

# the same virtual IP address from the pool that was

# previously assigned.

ifconfig-pool-persist ipp.txt

#ifconfig 10.7.0.1 255.255.255.0 # openvpn gateway

#ifconfig-pool 10.7.0.2 10.1.0.11 255.255.255.0 # ip range for openvpn client 



# Configure server mode for ethernet bridging.

# You must first use your OS's bridging capability

# to bridge the TAP interface with the ethernet

# NIC interface.  Then you must manually set the

# IP/netmask on the bridge interface, here we

# assume 10.8.0.4/255.255.255.0.  Finally we

# must set aside an IP range in this subnet

# (start=10.8.0.50 end=10.8.0.100) to allocate

# to connecting clients.  Leave this line commented

# out unless you are ethernet bridging.

#server-bridge 10.7.0.1 255.255.255.0 10.7.0.50 10.7.0.100



# Push routes to the client to allow it

# to reach other private subnets behind

# the server.  Remember that these

# private subnets will also need

# to know to route the OpenVPN client

# address pool (10.8.0.0/255.255.255.0)

# back to the OpenVPN server.

#push "route 10.7.0.0 255.255.255.0"

;push "route 192.168.20.0 255.255.255.0"



# To assign specific IP addresses to specific

# clients or if a connecting client has a private

# subnet behind it that should also have VPN access,

# use the subdirectory "ccd" for client-specific

# configuration files (see man page for more info).



# EXAMPLE: Suppose the client

# having the certificate common name "Thelonious"

# also has a small subnet behind his connecting

# machine, such as 192.168.40.128/255.255.255.248.

# First, uncomment out these lines:

;client-config-dir ccd

;route 192.168.40.128 255.255.255.248

# Then create a file ccd/Thelonious with this line:

#   iroute 192.168.40.128 255.255.255.248

# This will allow Thelonious' private subnet to

# access the VPN.  This example will only work

# if you are routing, not bridging, i.e. you are

# using "dev tun" and "server" directives.



# EXAMPLE: Suppose you want to give

# Thelonious a fixed VPN IP address of 10.9.0.1.

# First uncomment out these lines:

;client-config-dir ccd

;route 10.9.0.0 255.255.255.252

# Then add this line to ccd/Thelonious:

#   ifconfig-push 10.9.0.1 10.9.0.2



# Suppose that you want to enable different

# firewall access policies for different groups

# of clients.  There are two methods:

# (1) Run multiple OpenVPN daemons, one for each

#     group, and firewall the TUN/TAP interface

#     for each group/daemon appropriately.

# (2) (Advanced) Create a script to dynamically

#     modify the firewall in response to access

#     from different clients.  See man

#     page for more info on learn-address script.

;learn-address ./script



# If enabled, this directive will configure

# all clients to redirect their default

# network gateway through the VPN, causing

# all IP traffic such as web browsing and

# and DNS lookups to go through the VPN

# (The OpenVPN server machine may need to NAT

# the TUN/TAP interface to the internet in

# order for this to work properly).

# CAVEAT: May break client's network config if

# client's local DHCP server packets get routed

# through the tunnel.  Solution: make sure

# client's local DHCP server is reachable via

# a more specific route than the default route

# of 0.0.0.0/0.0.0.0.

#push "redirect-gateway"

push "redirect-gateway def1"





# Certain Windows-specific network settings

# can be pushed to clients, such as DNS

# or WINS server addresses.  CAVEAT:

push "dhcp-option DNS 10.7.0.1"

#push "dhcp-option DNS 208.67.220.220"

#push "dhcp-option WINS 10.7.0.1"



# Uncomment this directive to allow different

# clients to be able to "see" each other.

# By default, clients will only see the server.

# To force clients to only see the server, you

# will also need to appropriately firewall the

# server's TUN/TAP interface.

#client-to-client



# Uncomment this directive if multiple clients

# might connect with the same certificate/key

# files or common names.  This is recommended

# only for testing purposes.  For production use,

# each client should have its own certificate/key

# pair.

#

# IF YOU HAVE NOT GENERATED INDIVIDUAL

# CERTIFICATE/KEY PAIRS FOR EACH CLIENT,

# EACH HAVING ITS OWN UNIQUE "COMMON NAME",

# UNCOMMENT THIS LINE OUT.

;duplicate-cn



# The keepalive directive causes ping-like

# messages to be sent back and forth over

# the link so that each side knows when

# the other side has gone down.

# Ping every 10 seconds, assume that remote

# peer is down if no ping received during

# a 120 second time period.

keepalive 10 120



# For extra security beyond that provided

# by SSL/TLS, create an "HMAC firewall"

# to help block DoS attacks and UDP port flooding.

#

# Generate with:

#   openvpn --genkey --secret ta.key

#

# The server and each client must have

# a copy of this key.

# The second parameter should be '0'

# on the server and '1' on the clients.

;tls-auth ta.key 0 # This file is secret



# Select a cryptographic cipher.

# This config item must be copied to

# the client config file as well.

;cipher BF-CBC        # Blowfish (default)

;cipher AES-128-CBC   # AES

;cipher DES-EDE3-CBC  # Triple-DES



# Enable compression on the VPN link.

# If you enable it here, you must also

# enable it in the client config file.

comp-lzo



# The maximum number of concurrently connected

# clients we want to allow.

;max-clients 100



# It's a good idea to reduce the OpenVPN

# daemon's privileges after initialization.

#

# You can uncomment this out on

# non-Windows systems.

;user nobody

;group nobody



# The persist options will try to avoid

# accessing certain resources on restart

# that may no longer be accessible because

# of the privilege downgrade.

#persist-key

#persist-tun



# Output a short status file showing

# current connections, truncated

# and rewritten every minute.

status openvpn-status.log



# By default, log messages will go to the syslog (or

# on Windows, if running as a service, they will go to

# the "\Program Files\OpenVPN\log" directory).

# Use log or log-append to override this default.

# "log" will truncate the log file on OpenVPN startup,

# while "log-append" will append to it.  Use one

# or the other (but not both).

log         openvpn.log

;log-append  openvpn.log



# Set the appropriate level of log

# file verbosity.

#

# 0 is silent, except for fatal errors

# 4 is reasonable for general usage

# 5 and 6 can help to debug connection problems

# 9 is extremely verbose

verb 3



# Silence repeating messages.  At most 20

# sequential messages of the same message

# category will be output to the log.

;mute 20

I can ping server from remote machine but internet traffic is a no go.

openvpn how to states i need to:
"Pushing the redirect-gateway option to clients will cause all IP network traffic originating on client machines to pass through the OpenVPN server. The server will need to be configured to deal with this traffic somehow, such as by NATing it to the internet, or routing it through the server site's HTTP proxy.

On Linux, you could use a command such as this to NAT the VPN client traffic to the internet:

iptables -t nat -A POSTROUTING -s 10.8.0.0/24 -o eth0 -j MASQUERADE

This command assumes that the VPN subnet is 10.8.0.0/24 (taken from the server directive in the OpenVPN server configuration) and that the local Ethernet interface is eth0."

so, if I do

iptables -t nat -A POSTROUTING -s 10.7.0.0/24 -o eth0 -j MASQUERADE

i get:

iptables: No chain/target/match by that name

I have contacted vps live support, and after enabling iptables modules I was getting the same "error" ,I was told to send an e-mail to vps@eukhost.com as he needs take this matter to the supervisor.

h**p://www.eukhost.com/forums/f29/openvpn-linux-vps-667/ written by UKShane helped a lot but there is no mention of iptables

any help/suggestion is more than welcome.

Thanks a lot
Zeljko

**Rsync** · #2 (**permalink**) 30-06-2009, 11:04

Hello Zeljko,

I have investigated and found that your VPS is hosted on a Virtuozzo 3 Node and Masquerading is not possible with the current Virtuozzo version [Virtuozzo 3] since it has not been virtualized as a module yet. You must use SNAT in your iptables NAT rule.
You can use the iptables as,

Quote:

# iptables -t nat -s clientIP -A POSTROUTING -j SNAT --to serverIP

SNAT [Source Network Address Translation] & MASQUERADE change the source address of a packet, whereas DNAT [Destination Network Address Translation] changes the destination address of a packet, hence DNAT is good for port forwarding. On previous versions of Virtuozzo, MASQUERADE wasn't supported for iptables, people used source NAT routing.

The practical difference between these two is that MASQUERADE can only map several ports whereas SNAT/DNAT can map to IP and ports together [AFAIK].
Both targets have port ranges you can specify, both mangle the source address of packets going out the interface (and magically do the reverse as packets come back) but with SNAT you choose the source address while with MASQUERADE picks the address of the interface.

I have created a test VPS on Virtuozzo4 node and tested the "MASQUERADE" module on it and its working fine on it, below are the test results.

Quote:

[root@test ~]# iptables -t nat -A POSTROUTING -o venet0 -j MASQUERADE
[root@test ~]#

If you want we can provide you a new VPS on our Virtuozzo 4 node. For new VPS on Virtuozzo 4 node you only need to email at our VPS support on vps[@]eukhost.com from your registered email address and they will provide you a new VPS.

**ametovic** · #3 (**permalink**) 30-06-2009, 11:38

thank you so much Rsync,

just a few questions if you don't mind:

Quote:

# iptables -t nat -s clientIP -A POSTROUTING -j SNAT --to serverIP

what is clientip and what is serverIP?

my server gets 10.7.0.1 and remote machine gets 10.7.0.6 from openvpn and the servers ext IP is 78.129.***.**

is this correct?

Quote:

iptables -t nat -s 10.7.0.0/24 -A POSTROUTING -j SNAT --to 78.129.***.**

or this?

Quote:

iptables -t nat -s 10.7.0.0/24 -A POSTROUTING -j SNAT --to 10.7.0.1

or none of the above?

if I wanted to move to Virtuozzo 4 node would I need to setup the server again?
how long is the down time?

Thanks a lot , I do appreciate it.
Zeljko

**Rsync** · #4 (**permalink**) 30-06-2009, 12:08

Hello Zeljko,

Quote:

iptables -t nat -s 10.7.0.0/24 -A POSTROUTING -j SNAT --to 78.129.***.**

Is the correct one.

Quote:

if I wanted to move to Virtuozzo 4 node would I need to setup the server again?
how long is the down time?

We will setup a new VPS with new IP address on the Virtuozzo 4 Hardware node and provide you the details for the same. You can then make your installation again on the new vps server as per your requirement and make the necessary DNS changes as per your convenience. Once everything starts working from the new VPS server, we will stop your old VPS.
Or
If your VPS is not having any script which is integrated with the IP address, then we can move your whole VPS as it is to a new node and add new IP address to it. In this process you will not have to move any data or configure any thing again on your new VPS, you will only need to make the DNS changes for your site pointing to new IP address.

Please let us know if you want us to proceed with the setup of new VPS.

**ametovic** · #5 (**permalink**) 30-06-2009, 12:45

thanks a gain for your reply,

if I am understanding this corectly , IP address will change in both cases? if thats the case its too much of a trouble to change all the DNS.

there must be a way of doing openvpn on Virtuozzo 3 , I just cant figure it out.

Thanks a lot for your help so far

Zeljko

**Rsync** · #6 (**permalink**) 30-06-2009, 13:06

Hello Zeljko,

Yes, in both cases IP address would change as our all virtuozzo 4 nodes are on different subnet IP range.
To get the Open VPN working on Virtuozzo 3, you will have to use SNAT in your iptables NAT rule, because Masquerading is not possible with the current Virtuozzo version.

**ametovic** · #7 (**permalink**) 30-06-2009, 13:52

Hi Rsync,

just a quick note to thank you for all your help.

Opnvpn is now working , so there is no need to move the server to Virtuozzo 4.

in case anyone needs a good how-to h**p://www.webhostingtalk.com/showthread.php?t=595436

sorry I am not allowed to post links

Cheers
Zeljko

**Rsync** · #8 (**permalink**) 30-06-2009, 13:59

Hello Zeljko,

Great to hear that Open VPN is working fine