// Module included in the following assemblies:
//
// * virt/vm_networking/virt-connecting-vm-to-secondary-udn.adoc

:_mod-docs-content-type: PROCEDURE
[id="virt-udn-osa-hipersockets-ibm-z_{context}"]
= Configuring OSA and HiperSockets adapters for virtual machine networking on {ibm-z-name}

[role="_abstract"]
You can configure OSA and HiperSockets interfaces on {ibm-z-name} for virtual machine networking by enabling Virtual NIC Characteristics (VNICC) attributes on the qeth driver. Without them, the qeth driver silently drops packets destined for virtual machine MAC addresses.

.Prerequisites

* You have the bus ID of the qeth network device, for example `0.0.1100`.
* The `chzdev` command-line tool is available on the host node.

.Procedure

. Enable flooding on the qeth device by running the following command:
+
[source,terminal]
----
$ echo 1 > /sys/devices/qeth/0.0.1100/vnicc/flooding
----

. Enable multicast flooding on the qeth device by running the following command:
+
[source,terminal]
----
$ echo 1 > /sys/devices/qeth/0.0.1100/vnicc/mcast_flooding
----

. Enable MAC address learning on the qeth device by running the following command:
+
[source,terminal]
----
$ echo 1 > /sys/devices/qeth/0.0.1100/vnicc/learning
----

. Or, enable MAC address learning by using `chzdev`:
+
[source,terminal]
----
$ sudo chzdev <device_bus_id> vnicc/learning=1
----
+
where:

`chzdev`:: Specifies the tool to configure {ibm-z-name} devices.
`<device_bus_id>`:: Specifies the bus ID of the qeth network device, for example `0.0.1100`.
`vnicc/learning=1`:: Enables MAC address learning.
