NAME¶
ip-netns - process network namespace management
SYNOPSIS¶
ip [
OPTIONS ]
netns {
COMMAND |
help }
ip netns {
list }
ip netns {
add |
delete }
NETNSNAME
ip netns identify PID
ip netns pids NETNSNAME
ip netns exec NETNSNAME command ...
ip netns monitor
DESCRIPTION¶
A network namespace is logically another copy of the network stack, with its own
routes, firewall rules, and network devices.
By convention a named network namespace is an object at
/var/run/netns/NAME that can be opened. The file descriptor resulting
from opening
/var/run/netns/NAME refers to the specified network
namespace. Holding that file descriptor open keeps the network namespace
alive. The file descriptor can be used with the
setns(2) system call to
change the network namespace associated with a task.
For applications that are aware of network namespaces, the convention is to look
for global network configuration files first in
/etc/netns/NAME
/
then in
/etc/. For example, if you want a different version of
/etc/resolv.conf for a network namespace used to isolate your vpn you
would name it
/etc/netns/myvpn/resolv.conf.
ip netns exec automates handling of this configuration, file convention
for network namespace unaware applications, by creating a mount namespace and
bind mounting all of the per network namespace configure files into their
traditional location in /etc.
- ip netns list - show all of the named network
namespaces
-
This command displays all of the network namespaces in /var/run/netns
- ip netns add NAME - create a new named network
namespace
-
If NAME is available in /var/run/netns/ this command creates a new network
namespace and assigns NAME.
- ip netns delete NAME - delete the name of a network
namespace
-
If NAME is present in /var/run/netns it is umounted and the mount point is
removed. If this is the last user of the network namespace the network
namespace will be freed, otherwise the network namespace persists until it
has no more users. ip netns delete may fail if the mount point is in use
in another mount namespace.
- ip netns identify PID - Report network namespaces names
for process
-
This command walks through /var/run/netns and finds all the network
namespace names for network namespace of the specified process.
- ip netns pids NAME - Report processes in the named
network namespace
-
This command walks through proc and finds all of the process who have the
named network namespace as their primary network namespace.
- ip netns exec NAME cmd ... - Run cmd in the named
network namespace
-
This command allows applications that are network namespace unaware to be
run in something other than the default network namespace with all of the
configuration for the specified network namespace appearing in the
customary global locations. A network namespace and bind mounts are used
to move files from their network namespace specific location to their
default locations without affecting other processes.
- ip netns monitor - Report as network namespace names are
added and deleted
-
This command watches network namespace name addition and deletion events and
prints a line for each event it sees.
EXAMPLES¶
ip netns list
Shows the list of current named network
namespaces
ip netns add vpn
Creates a network namespace and names it
vpn
ip netns exec vpn ip link set lo up
Bring up the loopback interface in the vpn
network namespace.
SEE ALSO¶
ip(8)
AUTHOR¶
Original Manpage by Eric W. Biederman