File: //usr/share/system-config-network/help/network-aliases.html
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><A
NAME="NETWORK-ALIASES"
></A
>Chapter 13. Device Aliases</H1
><P
> <I
CLASS="FIRSTTERM"
>Device aliases</I
> are virtual devices associated
with the same physical hardware, but they can be activated at the same
time to have different IP addresses. They are commonly represented as
the device name followed by a colon and a number (for example,
eth0:1). They are useful if you want to have multiple IP address for a
system, but the system only has one network card.
</P
><P
> After configuring the Ethernet device, such as
<TT
CLASS="COMPUTEROUTPUT"
>eth0</TT
>, to use a static IP address (DHCP
does not work with aliases), go to the <B
CLASS="GUILABEL"
>Devices</B
> tab
and click <B
CLASS="GUIBUTTON"
>New</B
>. Select the Ethernet card to
configure with an alias, set the static IP address for the alias, and
click <B
CLASS="GUIBUTTON"
>Apply</B
> to create it. Since a device already
exists for the Ethernet card, the one just created is the alias such as
<TT
CLASS="COMPUTEROUTPUT"
>eth0:1</TT
>.
</P
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> If you are configuring an Ethernet device to have an alias, neither
the device nor the alias can be configured to use DHCP. You must
configure the IP addresses manually.
</P
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><P
> <A
HREF="network-aliases.html#FIG-NETWORK-ALIASES"
>Figure 13-1</A
> shows an example of one alias for
the <TT
CLASS="COMPUTEROUTPUT"
>eth0</TT
> device. Notice the
<TT
CLASS="COMPUTEROUTPUT"
>eth0:1</TT
> device — the first alias
for <TT
CLASS="COMPUTEROUTPUT"
>eth0</TT
>. The second alias for
<TT
CLASS="COMPUTEROUTPUT"
>eth0</TT
> would have the device name
<TT
CLASS="COMPUTEROUTPUT"
>eth0:2</TT
>, and so on. To modify the
settings for the device alias such as whether to activate it at boot
time and the alias number, select it from the list and click the
<B
CLASS="GUIBUTTON"
>Edit</B
> button.
</P
><DIV
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><A
NAME="FIG-NETWORK-ALIASES"
></A
><DIV
CLASS="MEDIAOBJECT"
><P
><IMG
SRC="./figs/neat-aliases.png"></P
></DIV
><P
><B
>Figure 13-1. Network Device Alias Example</B
></P
></DIV
><P
> Select the alias and click the <B
CLASS="GUIBUTTON"
>Activate</B
> button to
activate the alias. If you have configured multiple profiles, select
which profiles in which to include it.
</P
><P
> To verify that the alias has been activated, use the
command <TT
CLASS="COMMAND"
>/sbin/ifconfig</TT
>. The output should show the
device and the device alias with different IP address:
</P
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><PRE
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><TT
CLASS="COMPUTEROUTPUT"
>eth0 Link encap:Ethernet HWaddr 00:A0:CC:60:B7:G4
inet addr:192.168.100.5 Bcast:192.168.100.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:161930 errors:1 dropped:0 overruns:0 frame:0
TX packets:244570 errors:0 dropped:0 overruns:0 carrier:0
collisions:475 txqueuelen:100
RX bytes:55075551 (52.5 Mb) TX bytes:178108895 (169.8 Mb)
Interrupt:10 Base address:0x9000
eth0:1 Link encap:Ethernet HWaddr 00:A0:CC:60:B7:G4
inet addr:192.168.100.42 Bcast:192.168.100.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Interrupt:10 Base address:0x9000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:5998 errors:0 dropped:0 overruns:0 frame:0
TX packets:5998 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1627579 (1.5 Mb) TX bytes:1627579 (1.5 Mb)</TT
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