| ip-netns(8) - phpMan
IP-NETNS(8) Linux IP-NETNS(8)
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 names‐
pace 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 iso‐
late your vpn you would name it /etc/netns/myvpn/resolv.conf.
ip netns exec automates handling of this configuration, file convention for network names‐
pace 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 names‐
pace 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 names‐
pace specific location to their default locations without affecting other pro‐
cesses.
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
iproute2 16 Jan 2013 IP-NETNS(8)
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