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20.4 Configuring a Network Connection with YaST
There are many supported networking types on Linux. Most of them use
different device names and the configuration files are spread over several
locations in the file system. For a detailed overview of the aspects of
manual network configuration, see Section 20.6, Configuring a Network Connection Manually.
During installation on a laptop, where NetworkManager is active by default, YaST
configures all interfaces that have been detected. On other machines, only
the first interface with link up (a network cable is connected) is
automatically configured. Additional hardware can be configured any time
on the installed system. The following sections describe the network
configuration for all types of network connections supported by
openSUSE.
20.4.1 Configuring the Network Card with YaST
To configure your wired or wireless network card in YaST, select
. After starting the module, YaST
displays the dialog with four tabs:
, ,
, and .
The tab allows to set general
networking options such as the use of NetworkManager, IPv6 and general DHCP
options. For more information, see
Configuring Global Networking Options.
The tab contains information about installed
network cards. Any properly detected network card is listed with its
name. You can manually add new cards, remove them or change their
configuration in this dialog. If you want to manually add and configure a
card that was not automatically detected, see
Configuring an Undetected Network Card. If you want to
change the configuration of an already configured card, see
Changing the Configuration of a Network Card.
The tab allows to set the hostname of the
machine and name the servers to be used. For more information, see
Configuring Hostname and DNS.
The tab is used for the configuration of
routing. See Configuring Routing for more
information.
Configuring Global Networking Options
The tab of the YaST module allows to set important global networking
options, such as the use of NetworkManager, IPv6 and DHCP client options. These
settings are applicable for all network interfaces.
In the choose the way network
connections are managed. If you want a NetworkManager desktop applet to manage
connections for all interfaces, choose . This option is well suited for switching between
multiple wired and wireless networks. If you do not run a desktop
environment (GNOME or KDE) or your computer is a Xen server, virtual
system, or provides network services such as DHCP or DNS in your
network, use the . For
more information on NetworkManager, see Section 10.0, Using NetworkManager, (↑ Start-Up ).
In the choose whether you want
to use the IPv6 protocol. It is possible to use IPv6 together with IPv4.
By default, IPv6 is activated. However, in networks not using IPv6
protocol, response times can be faster with IPv6 protocol disabled. If
you want to disable IPv6, uncheck the
option. This disables autoload of the kernel module for IPv6. All
changes will be applied after reboot.
In the configure options for the
DHCP client. If you want the DHCP client to ask the server to always
broadcast its responses, check . It may be needed if your machine is moving between
different networks. The must
be different for each DHCP client on a single network. If left empty, it
defaults to the hardware address of the network interface. However, if
you are running several virtual machines using the same network
interface and, therefore, the same hardware address, specify a unique
free-form identifier here.
The specifies a string used for the
hostname option field when dhcpcd sends messages to DHCP server. Some
DHCP servers update name server zones (forward and reverse records)
according to this hostname (Dynamic DNS). Also, some DHCP servers
require the option field to contain
a specific string in the DHCP messages from clients. Leave
AUTO to send the current hostname (that is the one
defined in /etc/HOSTNAME. Leave the option field
empty for not sending any hostname. If yo do not want to change the
default route according to the information from DHCP,
uncheck .
Changing the Configuration of a Network Card
To change the configuration of a network card, select a card from the
list of the detected cards in in YaST
and click . The dialog appears in which to adjust the card configuration
using the , , and
tabs. For information about wireless card
configuration, see Section 30.1.2, Configuration with YaST.
Configuring IP Addresses
You can set the IP adresss of the network card or the way its IP
address is determined in the tab of the
dialog. Both IPv4 and IPv6
addresses are supported. The network card can have (which is useful for bonding devices), a
(IPv4 or IPv6), or a
assigned via
and/or .
If using , select whether to use
(for IPv4), (for IPv6), or .
If possible, the first network card with link that is available during
the installation is automatically configured to use automatic address
setup via DHCP. In case of laptop computers where NetworkManager is active by
default, all network cards are configured.
DHCP should also be used if you are using a DSL line but with no static
IP assigned by the ISP (Internet Service Provider). If you decide to
use DHCP, configure the details in in the tab of the
dialog of the YaST network card
configuration module. Specify whether the DHCP client should ask the
server to always broadcast its responses in . This option may be needed if your machine is a
mobile client moving between networks. If you have a virtual host setup
where different hosts communicate through the same interface, an
is necessary to distinguish
them.
DHCP is a good choice for client configuration but it is not ideal for
server configuration. To set a static IP address, proceed as follows:
-
Select a card from the list of detected cards in the
tab of the YaST network card
configuration module and click .
-
In the tab, choose .
-
Enter the . Both IPv4 and IPv6 addresses
can be used. Enter the network mask in . If the IPv6 address is used, use for prefix length in format /64.
Optionally, you can enter a fully qualified
for this address, which will be written
to the /etc/hosts configuration file.
-
Click .
-
To activate the configuration, click .
If you use the static address, the name servers and default gateway are
not configured automatically. To configure name servers, proceed as
described in Configuring Hostname and DNS. To
configure a gateway, proceed as described in
Configuring Routing.
Changing the Device Name and Udev Rules
It is possible to change the device name of the network card when it is
used. It is also possible to determine whether the network card should
be identified by udev via its hardware (MAC) address or via the bus ID.
The later option is preferable in large servers to ease hot swapping of
cards. To set these options with YaST, proceed as follows:
-
Select a card from the list of detected cards in the
tab of the YaST module and click .
-
Go to the tab. The current device name is
shown in . Click
.
-
Select whether udev should identify the card by its or . The current MAC
address and bus ID of the card are shown in the dialog.
-
To change the device name, check the option and edit the name.
-
Click and .
-
To activate the configuration, click .
Changing Network Card Kernel Module
For some network cards, several kernel modules (drivers) may be
available. If the card is already configured, YaST allows to select a
kernel module to be used from a list of available suitable modules. It
is also possible to specify options for the kernel module. To set these
options with YaST, proceed as follows:
-
Select a card from the list of detected cards in the
tab of the YaST Network Settings module
and click .
-
Go to the tab.
-
Select the kernel module to be used in . Enter any options for the selected module in
in the form
option=value
. If more options are used, they should be space-separated.
-
Click and .
-
To activate the configuration, click .
Activating the Network Device
If you use the traditional method with ifup, you can configure your
device to either start during boot, on cable connection, on card
detection, manually, or never. To change device start-up, proceed as
follows:
-
In YaST select a card from the list of detected cards in
and click .
-
In the tab, select the desired entry from
.
Choose to start the device during the
system boot. With , the
interface is watched for any existing physical connection. With
, the interface is set as soon as
available. It is similar to the
option, and only differs in the fact that no error occurs if the
interface is not present at boot time. Choose
to control the interface manually with
ifup or KInternet. Choose
to not start the device at all. The is
similar to , but the interface is does
not shut down with the rcnetwork stop command. Use
this if you use an nfs or iscsi root file system.
-
Click .
-
To activate the configuration, click .
Usually, only the system administrator can activate and deactivate
network interfaces. If you want any user to be able to activate this
interface via KInternet, select .
Setting Up Maximum Transfer Unit Size
You can set a maximum transmission unit (MTU) for the interface. MTU
refers to the largest allowed packet size in bytes. A higher MTU brings
higher bandwidth efficiency. However, large packets can block up a slow
interface for some time, increasing the lag for further packets.
-
In YaST select a card from the list of detected cards in
and click .
-
In the tab, select the desired entry from
the list.
-
Click .
-
To activate the configuration, click .
Configuring the Firewall
Without having to enter the detailed firewall setup as described in
Section 33.4.1, Configuring the Firewall with YaST, you can determine the basic
firewall setup for your device as part of the device setup. Proceed as
follows:
-
Open the YaST module. In the
tab, select a card from the list of
detected cards and click .
-
Enter the tab of the dialog.
-
Determine the firewall zone to which your interface should be
assigned. The following options are available:
- Firewall Disabled
-
This option is available only if the firewall is disabled and the
firewall does not run at all. Only use this option, if your
machine is part of a greater network that is protected by an outer
firewall.
- Automatically Assign Zone
-
This option is available only if the firewall is enabled. The
firewall is running and the interface is automatically assigned to
a firewall zone. The zone which contains the keyword
any or the external zone will be used for such
an interface.
- Internal Zone (Unprotected)
-
The firewall is running, but does not enforce any rules to protect
this interface. Use this option, if your machine is part of a
greater network that is protected by an outer firewall. It is also
useful for the interfaces connected to the internal network, when
the machine has more network interfaces.
- Demilitarized Zone
-
A demilitarized zone is an additional line of defense in front of
an internal network and the (hostile) Internet. Hosts assigned to
this zone can be reached from the internal network and from the
Internet, but cannot access the internal network.
- External Zone
-
The firewall is running on this interface and fully protects it
against other—presumably hostile— network traffic.
This is the default option.
-
Click .
-
Activate the configuration by clicking .
Configuring an Undetected Network Card
Your card may not be detected correctly. In this case, the card is not
included in the list of detected cards. If you are sure that your system
includes a driver for your card, you can configure it manually. To
configure an undetected network card, proceed as follows:
-
In the dialog in YaST click .
-
In the dialog, set the of the interface from the available options and
. If the network card is a PCMCIA
or USB device, activate the respective check box and exit this dialog
with . Otherwise, you can define the kernel
to be used for the card and its
, if necessary.
-
Click .
-
Configure any needed options, such as the IP address, device
activation or firewall zone for the interface in the
, , and
tabs. For more information about the
configuration options, see
Changing the Configuration of a Network Card.
-
If you selected as the device type of the
interface, configure the wireless connection in the next dialog.
-
Click .
-
To activate the new network configuration, click
.
Configuring Hostname and DNS
If you did not change the network configuration during installation and
the wired card was already available, a hostname was automatically
generated for your computer and DHCP was activated. The same applies to
the name service information your host needs to integrate into a network
environment. If DHCP is used for network address setup, the list of
domain name servers is automatically filled with the appropriate data.
If a static setup is preferred, set these values manually.
To change the name of your computer and adjust the name server search
list, proceed as follows:
-
Go to the tab in the
module in YaST.
-
Enter the and, if needed, the
. The domain is especially important if
the machine is a mail server. Note that the hostname is global and
applies to all set network interfaces.
If you are using DHCP to get an IP address, the hostname of your
computer will be automatically set by the DHCP. You may want to
disable this behavior if you connect to different networks, because
they may assign different hostnames and changing the hostname at
runtime may confuse the graphical desktop. To disable using DHCP to
get an IP address uncheck .
If you are using DHCP to get an IP address, your hostname will be
written to /etc/hosts by default and be
resolvable as a 127.0.0.2 IP address. To disable
this uncheck but note,
that your hostname will not be resolvable without an active network.
-
In , select the way the DNS
configuration (name servers, search list, the content of the
/etc/resolv.conf file) is modified.
If the option is selected, the
configuration is handled by the netconfig script
which merges the data defined statically (with YaST or in the
configuration files) with data obtained dynamically (from the DHCP
client or NetworkManager). This default policy is sufficient in most
cases.
If the option is selected,
netconfig is not allowed to modify the
/etc/resolv.conf file. However, this file can be
edited manually.
If the option is selected, a
string defining the merge policy
should be specified. The string consists of comma-separated list of
interface names to be considered a valid source of settings. Except of
complete interface names, also basic wildcards to match multiple
interfaces are allowed. For example, eth* ppp? will
first target all eth and then all ppp0-ppp9 interfaces. There are two
special policy values that indicate how to apply the static settings
defined in the /etc/sysconfig/network/config
file:
- STATIC
-
The static settings have to be merged together with the dynamic
settings.
- STATIC_FALLBACK
-
The static settings are used only when no dynamic configuration is
avaliable.
For more information, see the man 8 netconfig.
-
Enter the and fill in the
list. Name servers must be specified
by IP addresses, such as 192.168.1.116, not by hostnames. Names specified in
the tab are domain names used for
resolving hostnames without a specified domain. If more than one
is used, separate domains whith
commas or white space.
-
To activate the configuration, click .
Configuring Routing
To make your machine communicate with other machines and other networks,
routing information must be given to make network traffic take the
correct path. If DHCP is used, this information is automatically
provided. If a static setup is used, this data must be added manually.
-
In YaST go to .
-
Enter the IP address of the . The
default gateway matches every possible destination, but if any other
entry exists that matches the required address, use this instead of
the default route.
-
More entries can be entered in the .
Enter the network IP address,
IP address and the
. Select the
through which the traffic to the defined network will be routed (the
minus sign stands for any device).
To omit any of these values, use the minus sign -.
To enter a default gateway into the table, use
default in the
field.
NOTE:
If more default routes are used, it is possible to specify the metric
option to determine which route has a higher priority. To specify the
metric option, enter - metric
number in
. The route with the highest metric is used
as default. If the network device is disconnected, its route will be
removed and the next one will be used.
However, the current kernel does not use metric in static routing,
only routing daemons like multipathd do.
-
If the system is a router, enable the
option in the .
-
To activate the configuration, click .
20.4.2 Modem
In the YaST Control Center, access the modem configuration under
. If your modem was not automatically detected, open the
dialog for manual configuration by clicking . Enter
the interface to which the modem is connected under .
HINT: CDMA and GPRS Modems
Configure supported CDMA and GPRS modems with the YaST
module just as you would configure regular
modems.
If you are behind a private branch exchange (PBX), you may need to enter
a dial prefix. This is often a zero. Consult the instructions that came
with the PBX to find out. Also select whether to use tone or pulse
dialing, whether the speaker should be on, and whether the modem should
wait until it detects a dial tone. The last option should not be enabled
if the modem is connected to an exchange.
Under , set the baud rate and the modem
initialization strings. Only change these settings if your modem was not
detected automatically or if it requires special settings for data
transmission to work. This is mainly the case with ISDN terminal
adapters. Leave this dialog by clicking . To
delegate control over the modem to the normal user without root
permissions, activate . In this way, a user without administrator
permissions can activate or deactivate an interface. Under , specify a regular expression. The
in KInternet, which can be modified by the
normal user, must match this regular expression. If this field is left
empty, the user cannot set a different
without administrator permissions.
In the next dialog, select the ISP. To choose from a predefined list of
ISPs operating in your country, select .
Alternatively, click to open a dialog in which to
provide the data for your ISP. This includes a name for the dial-up
connection and ISP as well as the login and password provided by your
ISP. Enable to be prompted for
the password each time you connect.
In the last dialog, specify additional connection options:
-
-
If you enable , set at least one name
server. Use this feature only if your Internet connection is
inexpensive, because there are programs that periodically request data
from the Internet.
-
-
This option is enabled by default, with the effect that the name
server address is updated each time you connect to the Internet.
-
-
If the provider does not transmit its domain name server after
connecting, disable this option and enter the DNS data manually.
-
-
If this options is enabled, the connection is automatically
reestablished after failure.
-
-
This option disables the detection of any prompts from the dial-up
server. If the connection build-up is slow or does not work at all,
try this option.
-
-
Selecting this option activates the firewall and sets the interface as
external. This way, you are protected from outside attacks for the
duration of your Internet connection.
-
-
With this option, specify a period of network inactivity after which
the modem disconnects automatically.
-
-
This opens the address configuration dialog. If your ISP does not
assign a dynamic IP address to your host, disable then enter your host's local IP address and the
remote IP address. Ask your ISP for this information. Leave
enabled and close the dialog by
selecting .
Selecting returns to the original dialog, which
displays a summary of the modem configuration. Close this dialog with
.
20.4.3 ISDN
Use this module to configure one or several ISDN cards for your system.
If YaST did not detect your ISDN card, click on
in the tab and manually select your card.
Multiple interfaces are possible, but several ISPs can be configured for
one interface. In the subsequent dialogs, set the ISDN options necessary
for the proper functioning of the card.
In the next dialog, shown in Figure 20-5, select the
protocol to use. The default is , but
for older or larger exchanges, select . If you are
in the US, select . Select your country in the
relevant field. The corresponding country code then appears in the field
next to it. Finally, provide your and the
if necessary. If you do not want to log
all your ISDN traffic, uncheck the
option.
defines how the ISDN interface should
be started: causes the ISDN driver to be
initialized each time the system boots.
requires you to load the ISDN driver as root with the command
rcisdn start. , used for
PCMCIA or USB devices, loads the driver after the device is plugged in.
When finished with these settings, select .
In the next dialog, specify the interface type for your ISDN card and add
ISPs to an existing interface. Interfaces may be either the
SyncPPP or the RawIP
type, but most ISPs operate in the SyncPPP mode,
which is described below.
The number to enter for depends on
your particular setup:
- ISDN Card Directly Connected to Phone Outlet
-
A standard ISDN line provides three phone numbers (called multiple
subscriber numbers, or MSNs). If the subscriber asked for more, there
may be up to 10. One of these MSNs must be entered here, but without
your area code. If you enter the wrong number, your phone operator
automatically falls back to the first MSN assigned to your ISDN line.
- ISDN Card Connected to a Private Branch Exchange
-
Again, the configuration may vary depending on the equipment
installed:
-
Smaller private branch exchanges (PBX) built for home purposes
mostly use the Euro-ISDN (EDSS1) protocol for internal calls. These
exchanges have an internal S0 bus and use internal numbers for the
equipment connected to them.
Use one of the internal numbers as your MSN. You should be able to
use at least one of the exchange's MSNs that have been enabled for
direct outward dialing. If this does not work, try a single zero.
For further information, consult the documentation delivered with
your phone exchange.
-
Larger phone exchanges designed for businesses normally use the 1TR6
protocol for internal calls. Their MSN is called EAZ and usually
corresponds to the direct-dial number. For the configuration under
Linux, it should be sufficient to enter the last digit of the EAZ.
As a last resort, try each of the digits from 1 to 9.
For the connection to be terminated just before the next charge unit is
due, enable . However, remember that may not
work with every ISP. You can also enable channel bundling (multilink PPP)
by selecting the corresponding option. Finally, you can enable firewall
for your link by selecting
and . To enable the normal user
without administrator permissions to activate or deactivate the
interface, select the .
opens a dialog in which to implement more
complex connection schemes, which are not relevant for normal home users.
Leave the dialog by selecting
.
In the next dialog, make IP address settings. If you have not been given
a static IP by your provider, select . Otherwise, use the fields provided to enter your
host's local IP address and the remote IP address according to the
specifications of your ISP. If the interface should be the default route
to the Internet, select . Each host can
only have one interface configured as the default route. Leave this
dialog by selecting .
The following dialog allows you to set your country and select an ISP.
The ISPs included in the list are call-by-call providers only. If your
ISP is not in the list, select . This opens the
dialog in which to enter all the
details for your ISP. When entering the phone number, do not include any
blanks or commas among the digits. Finally, enter your login and the
password as provided by the ISP. When finished, select
.
To use on a stand-alone workstation,
also specify the name server (DNS server). Most ISPs support dynamic DNS,
which means the IP address of a name server is sent by the ISP each time
you connect. For a single workstation, however, you still need to provide
a placeholder address like
192.168.22.99. If your ISP
does not support dynamic DNS, specify the name server IP addresses of the
ISP. If desired, specify a time-out for the connection—the period
of network inactivity (in seconds) after which the connection should be
automatically terminated. Confirm your settings with
. YaST displays a summary of the configured
interfaces. To activate these settings, select .
20.4.4 Cable Modem
In some countries it is quite common to access the Internet through the
TV cable network. The TV cable subscriber usually gets a modem that is
connected to the TV cable outlet on one side and to a computer network
card on the other (using a 10Base-TG twisted pair cable). The cable modem
then provides a dedicated Internet connection with a fixed IP address.
Depending on the instructions provided by your ISP, when configuring the
network card either select or
. Most providers today
use DHCP. A static IP address often comes as part of a special business
account.
For further information about the configuration of cable modems, read the
Support Database article on the topic, which is available online at
https://en.opensuse.org/SDB:Setting_Up_an_Internet_Connection_via_Cable_Modem_with_SuSE_Linux_8.0_or_Higher.
20.4.5 DSL
To configure your DSL device, select the module
from the YaST section. This YaST
module consists of several dialogs in which to set the parameters of DSL
links based on one of the following protocols:
-
PPP over Ethernet (PPPoE)
-
PPP over ATM (PPPoATM)
-
CAPI for ADSL (Fritz Cards)
-
Point-to-Point Tunneling Protocol (PPTP)—Austria
In the tab of the dialog, you will find a list of
installed DSL devices. To change the configuration of a DSL device,
select it in the list and click . If you click
, you can manually configure a new DSL device.
The configuration of a DSL connection based on PPPoE or PPTP requires
that the corresponding network card has already been set up in the
correct way. If you have not done so yet, first configure the card by
selecting
(see
Section 20.4.1, Configuring the Network Card with YaST). In the case of a DSL
link, addresses may be assigned automatically but not via DHCP, which is
why you should not enable the option .
Instead, enter a static dummy address for the interface, such as
192.168.22.1. In
, enter
255.255.255.0. If you are
configuring a stand-alone workstation, leave empty.
HINT:
Values in and are only placeholders. They are only needed to initialize
the network card and do not represent the DSL link as such.
In the first DSL configuration dialog (see
Figure 20-7), select the and the to which the DSL
modem is connected (in most cases, this is
eth0). Then use
to specify whether the DSL link should
be established during the boot process. Click to authorize the normal
user without root permissions to activate or deactivate the interface
with KInternet.
In the next dialog select your country and choose from a number of ISPs
operating in it. The details of any subsequent dialogs of the DSL
configuration depend on the options set so far, which is why they are
only briefly mentioned in the following paragraphs. For details on the
available options, read the detailed help available from the dialogs.
To use on a stand-alone workstation,
also specify the name server (DNS server). Most ISPs support dynamic
DNS—the IP address of a name server is sent by the ISP each time
you connect. For a single workstation, however, provide a placeholder
address like 192.168.22.99. If
your ISP does not support dynamic DNS, enter the name server IP address
provided by your ISP.
defines a period of network
inactivity after which to terminate the connection automatically. A
reasonable time-out value is between 60 and 300 seconds. If is disabled, it may be useful to set the time-out to
zero to prevent automatic hang-up.
The configuration of T-DSL is very similar to the DSL setup. Just select
as your provider and YaST opens the T-DSL
configuration dialog. In this dialog, provide some additional information
required for T-DSL—the line ID, the T-Online number, the user code,
and your password. All of these should be included in the information you
received after subscribing to T-DSL.
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