IF_MPADM(8) Maintenance Commands and Procedures IF_MPADM(8)

NAME

if_mpadm - administer interfaces in an IP multipathing group

SYNOPSIS

if_mpadm -d | -r ifname

DESCRIPTION

The if_mpadm utility administers IP interfaces that are part of an IP
Multipathing (IPMP) group. Currently, administration is limited to
offlining IP interfaces and undoing previous offline operations.

When an IP interface is taken offline, all IP data traffic that was
flowing over the IP interface is moved to another IP interface in the
IPMP group. In addition, all UP IP addresses hosted on the IP
interface are brought down, causing in.mpathd(8) to stop probe-based
failure detection on the IP interface. As a result, an offline IP
interface will not be used for any inbound or outbound IP traffic.
Only IP interfaces that are in an IPMP group may be brought offline.
If the IP interface is the last functioning interface in the IPMP
group, the offline operation will fail.

When an offline operation is undone, any IP addresses hosted on that
IP interface are brought UP and will be considered by in.mpathd for
probe-based failure detection. In addition, provided the IP interface
is otherwise active (see in.mpathd(8)), it will again be used to send
and receive IP data traffic for the IPMP group. Note that not all
offline operations can be undone. For instance, in.mpathd may have
offlined an IP interface because its hardware address was not unique
within its IPMP group. The ipmpstat utility can be used to determine
why an IP interface is offline, identify which IP interfaces in a
group are being used for inbound and outbound IP traffic, and more;
see ipmpstat(8).

OPTIONS

The if_mpadm utility supports the following options:

-d ifname
Offline the IP interface specified by ifname. If ifname
is not in an IPMP group, or the offline would cause the
IPMP group to lose network connectivity, the operation
will fail.


-r ifname
Undo a previous offline of the IP interface specified by
ifname. If ifname is not offline, the operation will
fail.

EXAMPLES

Example 1: Offlining an IP Interface

The following command offlines the IP interface under0, causing any
IP packets that were being sent and received through it to be handled
by another IP interface in its group.


example% if_mpadm -d under0

Example 2: Undoing a Previous Offline Operation

Use the following command to undo the operation in the previous
example:


example% if_mpadm -r under0

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Unstable |
+--------------------+-----------------+

SEE ALSO

attributes(7), ifconfig(8), in.mpathd(8), ipmpstat(8)

DIAGNOSTICS

cannot offline: no other functioning interfaces are in its IPMP
group.
Description:


This message means that offlining the IP interface would leave
the IPMP group without network connectivity.


cannot offline: not a physical interface or not in an IPMP group
Description:


This means that the IP interface is not an underlying interface
in an IPMP group, and therefore is not eligible to be offlined.


September 2, 2015 IF_MPADM(8)