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