Virtual network device (venet) is the default network device for a container. This network device looks like a point-to-point connection between container and the host system. It does packet switching based on IP header. This is a default network device for container (an alternative is veth device).
Venet device is created automatically on container start. Vzctl scripts set up an appropriate IP address and other settings on venet inside a container.
Contents
Usage
Kernel module
First of all, check that vznetdev module is loaded:
# lsmod | grep vznetdev
If it is not, load the module:
# modprobe vznetdev
You might want to check /etc/init.d/vz script to make sure the module gets loaded during startup.
Adding IP address to a container
vzctl set <CTID> --ipadd <IP1>[,<IP2>,...] [--save]
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Note: This option is incremental, so IP addresses are added to already existing ones. |
Example
vzctl set 101 --ipadd 10.0.0.1 --save
After executing this command IP address 10.0.0.1 will be added to container 101 and IP configuration will be saved to a container configuration file.
Removing IP address from a container
vzctl set <CTID> --ipdel <IP1>[,<IP2>,...] [--save] vzctl set <CTID> --ipdel all [--save]
Example
vzctl set 101 --ipdel 10.0.0.1
After executing this command IP address 10.0.0.1 will be removed from container 101, but IP configuration will not be changed in container config file. And after container reboot IP address 10.0.0.1 will be assigned to this container again.
Sysctl
You will need to configure some sysctl parameters to get your venet devices working. Please have a look at the Installation_on_Debian#sysctl section.
IPv6
To setup IPv6 networking with venet you'll need to enable the following in your sysctl.conf:
net.ipv6.conf.default.forwarding = 1
net.ipv6.conf.all.forwarding = 1
In IPv6 you can't control forwarding per device, forwarding control has to take place in ip6tables, so all interfaces will forward IPv6 traffic.
If you enable IPv6 forwarding for your interfaces, Linux assumes your host to act like a router and will ignore 'Router Advertisments' (see Neighbor Discovery Protocol or Linux IPv6 Howto).
You will as well need to configure a new v6 default gateway for your host:
ip addr add 2001:1:1:1:0::2/64 dev eth0
route -6 add default gw 2001:1:1:1:0::1
You can add these commands to your existing network configuration on Debian/Linux:
iface eth0 inet static
address 213.235.253.206
netmask 255.255.255.240
network 213.235.253.192
broadcast 213.235.253.207
gateway 213.235.253.193
up ip addr add 2001:1:1:1:0::2/64 dev eth0
up route -6 add default gw 2001:1:1:1:0::1
down ip addr del 22001:1:1:1:0::2/64 dev eth0