Changes

 '''IP forwarding should be turned on, ''' on the hardware node in order for container networking to work. Make sure it is turned on:

The syntax of /etc/sysctl.conf has changed to :

=== IP conntracks Enable iptables in OpenVZ 7/Virtuozzo 7===IP connection tracking should be enabled for CT0.If you use OpenVZ 7/Virtuozzo 7 and want to manage iptables through iptables-services you must disable firewalld and enable iptables:  # systemctl stop firewalld # systemctl mask firewalld # yum install iptables-services # systemctl enable iptables  == How to create the container and attach network properties to it == Create the container:

and reboot # prlctl set 100700 --ipadd 192.168.0.101/24 # prlctl set 100700 --nameserver 8.8.8.8

options ip_conntrack ip_conntrack_disable_ve0=1# prlctl start 100700

== How To enable the [[container]]s, which have only internal IP addresses, to provide access for container to the Internet ==, SNAT (Source Network Address Translation, also known as IP masquerading) should be configured on the [[Hardware Node]]. This is ensured by the standard Linux <tt>iptables</tt> utility.

To enable the [[container]]s, which have only internal IP addresses, to access the Internet, SNAT (Source Network Address Translation, also known as IP masquerading) should be configured on the [[Hardware Node]]. This is ensured by the standard Linux <tt>iptables</tt> utility. To perform a simple SNAT setup, execute the following command on the [[Hardware Node]]:

where <tt>src_net</tt> is a range of IP addresses of containers to be translated by SNAT, and <tt>ip_address</tt> is the external IP address of your [[Hardware Node]]. The format of src_net is xx.xx.xx.xx/xx ([[w:CIDR|CIDR notation]]). For example to specify IP addresses from 192.168.2.1 through 192.168.2.127 use:

# iptables -t nat -A POSTROUTING -s 192.168.2.0/25 24 -o eth0 -j SNAT --to ip_address

{{Note|For a Debian O.S v4 or v5 Hardware Node, Or you may need to allow a forward rule. The table still being the default table (filter) but the chain is FORWARD can just use:

<pre> # /sbin/iptables -A FORWARD -s 172.16.150.0/24 -j ACCEPT# /sbin/iptables t nat -A FORWARD POSTROUTING -d 172.16.150.0/24 o eth0 -j ACCEPT</pre>}}MASQUERADE

If you are using an iptables firewall (for example the default RedHat/CentOS firewall), don't Do not forget to allow outgoing connections from your containers. For example if you are using the subnet 172.16.150.0/24 for save your VMs, you should do the following:<pre># /sbin/iptables -A RH-Firewall-1-INPUT -s 172.16.150.0/24 -j ACCEPT# /sbin/iptables-save > /etc/sysconfig/iptables# /sbin/service new iptables restart</pre>rules

{{Note|If the above is not working then check if one of the following solutions does the trick.}}1. If you are using stable (currently 2.6.8-based) kernel, then to enable SNAT for the containers on your local network you need to explicitly enable connection tracking in [[CT0]]. Make sure that the following string is present in the <tt>/etc/modprobe.conf</tt> file:<pre>options ip_conntrack ip_conntrack_enable_ve0=1</pre>== Firewall ===

{{Note|in kernels later than 2For Debian hardware node, you may need to allow a forward rule.6.8, connection tracking The table still being the default table (filter) but the chain is enabled by default}}FORWARD:

In case it is not, add this string to the file by means of any text editor (for example, vi) # iptables -A FORWARD -s 192.168. This setting is not needed for kernels more recent than 2.60/24 -j ACCEPT # iptables -A FORWARD -d 192.8, since connection tracking for [[CT0]] is enabled by default in those kernels168.2.0/24 -j ACCEPT

2. For unknown reasons the above didn't work on a Debian host. The solution is to do it in an init.d script as follows:<pre>modprobe ip_conntrack ip_conntrack_enable_ve0=1<default RedHat/pre>Make sure that this module is loaded before any of the other iptables-modules are loaded! Also remember that if this module is loaded without the optionCentOS firewall, unloading and reloading doesn't work! You need to reboot the computer.allow outgoing connections from your containers, for example:

{{Note|in kernels later than # iptables -A RH-Firewall-1-INPUT -s 192.168.2.6.8, connection tracking is enabled by default}}0/24 -j ACCEPT

{{Note| you may need to modify the /etc/vz/vz.conf file to include:}} <pre>IPTABLES="iptable_filter iptable_mangle ipt_limit ipt_multiport ipt_tos ipt_TOS ipt_REJECT ipt_TCPMSS ipt_tcpmss ipt_ttl ipt_LOG ipt_length ip_conntrack ip_conntrack_ftp ip_conntrack_irc ipt_conntrack ipt_state ipt_helper iptable_nat ip_nat_ftp ip_nat_irc ipt_REDIRECT"</pre>== Test ===

Now you should be able to reach internet from yours [[your container]]:

<pre> # prlctl enter 100700 vzctl exec <container ID> # ping www.openvz.org</pre>