1.6 KiB
Container Networking
When you create a container using nixos-container create
, it gets it
own private IPv4 address in the range 10.233.0.0/16
. You can get the
container's IPv4 address as follows:
# nixos-container show-ip foo
10.233.4.2
$ ping -c1 10.233.4.2
64 bytes from 10.233.4.2: icmp_seq=1 ttl=64 time=0.106 ms
Networking is implemented using a pair of virtual Ethernet devices. The
network interface in the container is called eth0
, while the matching
interface in the host is called ve-container-name
(e.g., ve-foo
).
The container has its own network namespace and the CAP_NET_ADMIN
capability, so it can perform arbitrary network configuration such as
setting up firewall rules, without affecting or having access to the
host's network.
By default, containers cannot talk to the outside network. If you want that, you should set up Network Address Translation (NAT) rules on the host to rewrite container traffic to use your external IP address. This can be accomplished using the following configuration on the host:
{
networking.nat.enable = true;
networking.nat.internalInterfaces = ["ve-+"];
networking.nat.externalInterface = "eth0";
}
where eth0
should be replaced with the desired external interface.
Note that ve-+
is a wildcard that matches all container interfaces.
If you are using Network Manager, you need to explicitly prevent it from managing container interfaces:
{
networking.networkmanager.unmanaged = [ "interface-name:ve-*" ];
}
You may need to restart your system for the changes to take effect.