22.6.2. Quick Reference for Adding Network Devices

There are several basic tasks for adding a network interface on IBM System z.

Load the device driver.
Create the group device.
Configure the device.
Set the device online.
Define the alias (if needed).
Create a configuration script.
Activate the device.

The following sections provide basic information for each task of each IBM System z network device driver.

22.6.2.1. Working With the LCS Device Driver

The LAN channel station (LCS) device driver supports OSA-2 Ethernet/Token Ring, OSA-Express Fast Ethernet in non-QDIO mode, and OSA-Express High Speed Token Ring in non-QDIO mode. For z990, the LCS driver also supports Gigabit Ethernet in non-QDIO mode (including 1000Base-T).

Based on the type of interface being added, the LCS driver assigns one of two base interface names: ethn for OSA-Express Fast Ethernet and Gigabit Ethernet trn for Token Ring, where n is an integer that uniquely identifies the device. n is 0 for the first device of that type, 1 for the second, and so on.

Load the device driver:
```
# modprobe lcs
```
Create the group device:
```
# echo read_device_bus_id,write_device_bus_id >
		/sys/bus/ccwgroup/drivers/lcs/group
```
Due to the length of this command, it has been broken into two lines.
Configure the device.
OSA cards can provide up to 16 ports for a single CHPID. By default, the LCS group device uses port 0. To use a different port, issue a command similar to the following:
```
# echo portno > /sys/bus/ccwgroup/drivers/lcs/device_bus_id/portno
```
For more information about configuration of the LCS driver, refer to the following:
http://www-128.ibm.com/developerworks/linux/linux390/october2005_documentation.html#3 (Linux for IBM System z and S/390 Device Drivers, Features, and Commands)

Set the device online:

# echo 1 > /sys/bus/ccwgroup/drivers/lcs/read_device_bus_id/online

Define the alias.
Based on the type interface being added, add a line to /etc/modprobe.conf that is similar to one of the following:
```
ethn alias lcs
trn alias lcs
```

Create a configuration script.

Create a file in /etc/sysconfig/network-scripts/ with a name like one of the following:

ifcfg-ethn
ifcfg-trn

The file should look similar to the following:

/etc/sysconfig/network-scripts/ifcfg-eth0
# IBM LCS
DEVICE=eth0
BOOTPROTO=static
HWADDR=00:06:29:FB:5F:F1
IPADDR=9.12.20.136
NETMASK=255.255.255.0
ONBOOT=yes
NETTYPE=lcs
SUBCHANNELS=0.0.09a0,0.0.09a1
PORTNAME=0
TYPE=Ethernet

Based on the type interface being added, the DEVICE parameter should be one of the following:

DEVICE=ethn
DEVICE=trn

Activate the device.
Based on the type interface being added, issue an ifup command:
```
# ifup ethn
# ifup trn
```