F.6. Adding a Network Device
The process of adding a network device has changed greatly for Red Hat Enterprise Linux. This is due in part to the migration of the 2.4 kernel to the 2.6 kernel:
The proc file system is no longer used to control or obtain status on network devices.
The new sys file system now provides facilities for controlling devices.
/sys/class/net/<interface_name>/device now provides status on active devices.
<interface_name> is a name such as eth0 or ctc2 that is given to a network interface by the device driver when the device is configured.
/etc/chandev.conf no longer exists.
The sys file system now contains the information that was placed in /etc/chandev.conf.
/etc/modules.conf no longer exists.
Network interface alias specifications are now placed in /etc/modprobe.conf.
Section F.6.1 Adding a qeth Device describes in detail how to add a qeth device to an existing instance of Red Hat Enterprise Linux. Section F.6.2 Quick Reference for Adding Network Devices is a quick reference for installing other zSeries network interfaces.
F.6.1. Adding a qeth Device
First, determine whether the qeth device driver modules are loaded.
# lsmod | grep qeth qeth 135240 0 qdio 45360 2 qeth ipv6 303984 13 qeth ccwgroup 15104 1 qeth |
If the output of the lsmod command shows that the modules are not loaded, you must run the modprobe command to load them:
# modprobe qeth |
Next, create a qeth group device.
# echo <read_device_bus_id>,<write_device_bus_id>,<data_device_bus_id> > /sys/bus/ccwgroup/drivers/qeth/group |
Due to the length of this command, it has been broken into two lines.
In the following example, read_device_bus_id is 0.0.0600, write_device_bus_id is 0.0.0601, and data_device_bus_id is 0.0.0602. The device is a z/VM virtual NIC and the IP address to be assigned to this interface is 192.168.70.69.
# echo 0.0.0600,0.0.0601,0.0.0602 > /sys/bus/ccwgroup/drivers/qeth/group |
Next, verify that the qeth group device was created properly:
# ls /sys/bus/ccwgroup/drivers/qeth 0.0.0600 0.0.09a0 group notifier_register |
You may optionally add a portname. First, you must check to see if a portname is required:
# cat /sys/bus/ccwgroup/drivers/qeth/0.0.0600/portname no portname required |
The response indicates that you do not need to provide a portname.
To add a port name, check that the devices are offline, and then run the following command:
 | Note |
|---|---|
The device(s) must be offline when you add a portname. |
# echo <portname> > /sys/bus/ccwgroup/drivers/qeth/0.0.0600/portname |
Next, bring the device back online:
# echo 1 /sys/bus/ccwgroup/drivers/qeth/0.0.0600/online |
Then verify the state of the device:
# cat /sys/bus/ccwgroup/drivers/qeth/0.0.0600/online 1 |
A return value of "1" indicates that the device is online, while a return value '0' indicates that the device is offline.
Check to see what interface name was assigned to the device:
# cat /sys/bus/ccwgroup/drivers/qeth/0.0.0600/if_name eth1 |
To change the value of if_name, run the following command:
# echo <new_if_name> > /sys/bus/ccwgroup/drivers/qeth/0.0.0600/if_name |
You may optionally set additional parameters and features, depending on the way you are setting up your system and the features you require.
add_hhlen
broadcast_mode
buffer_count
canonical_macaddr
card_type
checksumming
chpid
detach_state
fake_broadcast
fake_ll
ipa_takeover
portno
priority_queueing
recover
route4
rxip
state
ungroup
vipa
For information on how these features work, refer to http://oss.software.ibm.com/developerworks/opensource/linux390/docu/lx26apr04dd01.pdf (Linux for zSeries and S/390 Device Drivers, Features, and Commands).
Now you need to create the configuration file for your new interface. The network interface configuration files are placed in /etc/sysconfig/network-scripts/.
The network configuration files use the naming convention ifcfg-<device>, where device is the value found in the if_name file in the qeth group device that was created earlier. In this example it is eth1.
If there is an existing configuration file for another device of the same type already defined, the simplest solution is to copy it to the new name.
# cd /etc/sysconfig/network-scripts # cp ifcfg-eth0 ifcfg-eth1 |
If you do not have a similar device defined you must create one. Use this example of ifcfg-eth0 as a template.
/etc/sysconfig/network-scripts/ifcfg-eth0 # IBM QETH DEVICE=eth0 BOOTPROTO=static HWADDR=00:06:29:FB:5F:F1 IPADDR=9.12.20.136 NETMASK=255.255.255.0 ONBOOT=yes NETTYPE=qeth SUBCHANNELS=0.0.09a0,0.0.09a1,0.0.09a2 TYPE=Ethernet |
Edit the new ifcfg-eth1 file.
Remove the HWADDR line for now.
Modify the DEVICE statement to reflect the contents of the if_name file from your ccwgroup.
Modify the IPADDR statement to reflect the IP address of your new interface.
Modify the NETMASK statement as needed.
If you want your new interface to be activated at boot time, then make sure ONBOOT is set to yes.
Make sure the SUBCHANNELS statement matches the hardware addresses for your qeth device.
/etc/sysconfig/network-scripts/ifcfg-eth1 # IBM QETH DEVICE=eth1 BOOTPROTO=static IPADDR=192.168.70.87 NETMASK=255.255.255.0 ONBOOT=yes NETTYPE=qeth SUBCHANNELS=0.0.0600,0.0.0601,0.0.0602 TYPE=Ethernet |
A qeth device requires an alias definition in /etc/modprobe.conf. Edit this file and add an alias for your interface.
/etc/modprobe.conf alias eth0 qeth alias eth1 qeth options dasd_mod dasd=0.0.0100,0.0.4b19 |
Now you can start the new interface:
# ifup eth1 |
Check the status of the interface:
# ifconfig eth1
eth1 Link encap:Ethernet HWaddr 02:00:00:00:00:01
inet addr:192.168.70.87 Bcast:192.168.70.255 Mask:255.255.255.0
inet6 addr: fe80::ff:fe00:1/64 Scope:Link
UP BROADCAST RUNNING NOARP MULTICAST MTU:1492 Metric:1
RX packets:23 errors:0 dropped:0 overruns:0 frame:0
TX packets:3 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:644 (644.0 b) TX bytes:264 (264.0 b) |
Note that the HWaddr field in the first line of the ifconfig command output. The value after that must be added to the ifcfg-eth1 file. Add a line like the following to that file:
HWADDR=02:00:00:00:00:01 |
Now ifcfg-eth1 looks similar to the following:
# IBM QETH DEVICE=eth1 HWADDR=02:00:00:00:00:01 BOOTPROTO=static IPADDR=192.168.70.69 NETMASK=255.255.255.0 ONBOOT=yes NETTYPE=qeth SUBCHANNELS=0.0.0600,0.0.0601,0.0.0602 TYPE=Ethernet |
Check the routing for the new interface:
# route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.70.0 * 255.255.255.0 U 0 0 0 eth1 9.12.20.0 * 255.255.255.0 U 0 0 0 eth0 169.254.0.0 * 255.255.0.0 U 0 0 0 eth1 default pdlrouter-if5.p 0.0.0.0 UG 0 0 0 eth0 |
Verify your changes by using the ping command to ping the gateway:
# ping -c 1 192.168.70.8 PING 192.168.70.8 (192.168.70.8) 56(84) bytes of data. 64 bytes from 192.168.70.8: icmp_seq=0 ttl=63 time=8.07 ms |
If the default route information has changed, you must also update /etc/sysconfig/network accordingly.
F.6.2. Quick Reference for Adding Network Devices
There are several basic tasks for adding a network interface on zSeries systems.
Load the device driver.
Create the group device or, for IUCV, create the IUCV device.
Configure the device.
Set the device online (not applicable to IUCV).
Define the alias (if needed).
Create a configuration script.
Activate the device.
The following sections provide basic information for each task of each zSeries network device driver.
F.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: eth<n> for OSA-Express Fast Ethernet and Gigabit Ethernet tr<n> 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://oss.software.ibm.com/developerworks/opensource/linux390/docu/lx26apr04dd01.pdf (Linux for zSeries 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:
eth<n> alias lcs tr<n> alias lcs
Create a configuration script.
Create a file in /etc/sysconfig/network-scripts/ with a name like one of the following:
ifcfg-eth<n> ifcfg-tr<n>
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=eth<n> DEVICE=tr<n>
Activate the device.
Based on the type interface being added, issue an ifup command:
# ifup eth<n> # ifup tr<n>
F.6.2.2. Working With the QETH Device Driver
The QETH network device driver supports zSeries HiperSockets, OSA-Express Fast Ethernet, Gigabit Ethernet (including 1000Base-T), High Speed Token Ring, and ATM features (running Ethernet LAN emulation) in QDIO mode.
Based on the type of interface being added, the QETH driver assigns one of three base interface names:
hsi<n> for HiperSocket devices
eth<n> for OSA-Express Fast Ethernet and Gigabit Ethernet
tr<n> for Token Ring
The value <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 qeth
Create the group device:
# echo <read_device_bus_id>,<write_device_bus_id>,<data_device_bus_id> > /sys/bus/ccwgroup/drivers/qeth/group
Due to the length of this command, it has been broken into two lines.
Configure the device.
For more information about configuration of the QETH driver, refer to the following:
http://oss.software.ibm.com/developerworks/opensource/linux390/docu/lx26apr04dd01.pdf (Linux for zSeries and S/390 Device Drivers, Features, and Commands)
Set the device online:
# echo 1 /sys/bus/ccwgroup/drivers/qeth/<read_device_bus_id>/nline
Define the alias.
Based on the type interface being added, add a line to /etc/modprobe.conf that is like one of the following:
hsi<n> alias qeth eth<n> alias qeth tr<n> alias qeth
Create a configuration script.
Create a file in /etc/sysconfig/network-scripts/ with a name like one of the following:
ifcfg-hsi<n> ifcfg-eth<n> ifcfg-tr<n>
The file should look like this:
/etc/sysconfig/network-scripts/ifcfg-eth0 # IBM QETH DEVICE=eth0 BOOTPROTO=static HWADDR=00:06:29:FB:5F:F1 IPADDR=9.12.20.136 NETMASK=255.255.255.0 ONBOOT=yes NETTYPE=qeth SUBCHANNELS=0.0.09a0,0.0.09a1,0.0.09a2 TYPE=Ethernet
Based on the type interface being added, the DEVICE parameter should be like one of the following:
DEVICE=hsi<n> DEVICE=eth<n> DEVICE=tr<n>
Activate the device.
Based on the type interface being added, issue an ifup command:
# ifup hsi<n> # ifup eth<n> # ifup tr<n>
F.6.2.3. Working With the CTC Device Driver
A Channel-to-Channel (CTC) connection is the typical high speed connection between mainframes. The CTC device driver can be used to establish a point-to-point TCP/IP or tty connection between two Linux for zSeries and S/390 instances or between a Linux for zSeries and S/390 instance and another mainframe operating system instance such as z/OS, OS/390, z/VM, or z/VSE.
The CTC driver assigns a base interface name like the following:
ctc<n> |
The value <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 ctc
Create the group device:
# echo <read_device_bus_id>,<write_device_bus_id> > /sys/bus/ccwgroup/drivers/ctc/group
Due to the length of this command, it has been broken into two lines.
Configure the device.
Set the protocol:
# echo <protocol> /sys/bus/ccwgroup/drivers/ctc/<device_bus_id>/protocol
Where <protocol> is 0, 1, 2, or 3.
0 — This protocol provides compatibility with peers other than OS/390, or z/OS, for example, a VM TCP service machine. This is the default.
1 — This protocol provides enhanced package checking for Linux peers.
2 — This protocol provides a CTC-based tty connection with a Linux peer.
3 — This protocol provides compatibility with OS/390 or z/OS peers.
For more information about configuration of the CTC driver, refer to the following:
http://oss.software.ibm.com/developerworks/opensource/linux390/docu/lx26apr04dd01.pdf (Linux for zSeries and S/390 Device Drivers, Features, and Commands)
Set the device online:
# cho 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 like the following:
ctc<n> alias ctc
Create a configuration script.
Create a file in /etc/sysconfig/network-scripts/ with a name like the following:
ifcfg-ctc<n>
The file should look like the following:
/etc/sysconfig/network-scripts/ifcfg-ctc0 # IBM CTC DEVICE=ctc0 BOOTPROTO=static IPADDR=192.168.70.136 GATEWAY=172.16.70.136 NETMASK=255.255.255.255 ONBOOT=yes SUBCHANNELS=0.0.1b00,0.0.1b01 NETTYPE=ctc CTCPROT=0 TYPE=CTC
Activate the device.
Based on the type interface being added, issue an ifup command:
# ifup ctc<n>
F.6.2.4. Working With the IUCV Device Driver
The Inter-User Communication Vehicle (IUCV) is a VM communication facility that enables a program running in one VM guest to communicate with another VM guest, with a control program, or even with itself. The Linux for zSeries and S/390 IUCV device driver is a network device driver that uses IUCV to connect Linux guests running on different VM user IDs, or to connect a Linux guest to another VM guest such as a TCP/IP service machine.
The IUCV driver assigns a base interface name like the following:
iucv<n> |
The value <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 netiucv
Create the IUCV device:
# echo <peer_id> > /sys/bus/iucv/drivers/netiucv/connection
The value of <peer_id> is the guest ID of the VM guest you want to connect to. The IUCV device driver interprets the ID as uppercase. This is usually TCPIP.
This creates a sysfs structure like the following:
cat /sys/bus/iucv/drivers/netiucv/netiucv<n>
The value <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.
Configure the device.
Set the maximum buffer size if needed:
# echo <value> > /sys/bus/iucv/drivers/netiucv/netiucv<n>/buffer
The <value> is the number of bytes you want to set. If you specify a value outside the valid range, the command is ignored.
The permissible range of values for the maximum buffer size depends on the MTU settings. It must be in the range <minimum MTU + header size> to <maximum MTU + header size>. The header space is typically 4 bytes. The default for the maximum buffer size is 32768 bytes (32 KB).
For more information on configuration of the IUCV driver, refer to the following:
http://oss.software.ibm.com/developerworks/opensource/linux390/docu/lx26apr04dd01.pdf (Linux for zSeries and S/390 Device Drivers, Features, and Commands)
Define the alias.
Based on the type interface being added, add a line to /etc/modprobe.conf that is like the following:
iucv<n> alias netiucv
Create a configuration script.
Create a file in /etc/sysconfig/network-scripts/ with a name like the following:
ifcfg-iucv<n>
The file should look like this:
/etc/sysconfig/network-scripts/ifcfg-iucv0 # IBM IUCV DEVICE=iucv0 BOOTPROTO=static IPADDR=192.168.70.136 GATEWAY=172.16.70.136 NETMASK=255.255.255.255 ONBOOT=yes NETTYPE=iucv PEERID=TCPIP TYPE=IUCV
Activate the device.
Based on the type interface being added, issue an ifup command like the following:
# ifup iucv<n>