summaryrefslogtreecommitdiffstats
path: root/Documentation/networking/alias.rst
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--Documentation/networking/alias.rst49
1 files changed, 49 insertions, 0 deletions
diff --git a/Documentation/networking/alias.rst b/Documentation/networking/alias.rst
new file mode 100644
index 0000000000..af7c5ee920
--- /dev/null
+++ b/Documentation/networking/alias.rst
@@ -0,0 +1,49 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===========
+IP-Aliasing
+===========
+
+IP-aliases are an obsolete way to manage multiple IP-addresses/masks
+per interface. Newer tools such as iproute2 support multiple
+address/prefixes per interface, but aliases are still supported
+for backwards compatibility.
+
+An alias is formed by adding a colon and a string when running ifconfig.
+This string is usually numeric, but this is not a must.
+
+
+Alias creation
+==============
+
+Alias creation is done by 'magic' interface naming: eg. to create a
+200.1.1.1 alias for eth0 ...
+::
+
+ # ifconfig eth0:0 200.1.1.1 etc,etc....
+ ~~ -> request alias #0 creation (if not yet exists) for eth0
+
+The corresponding route is also set up by this command. Please note:
+The route always points to the base interface.
+
+
+Alias deletion
+==============
+
+The alias is removed by shutting the alias down::
+
+ # ifconfig eth0:0 down
+ ~~~~~~~~~~ -> will delete alias
+
+
+Alias (re-)configuring
+======================
+
+Aliases are not real devices, but programs should be able to configure
+and refer to them as usual (ifconfig, route, etc).
+
+
+Relationship with main device
+=============================
+
+If the base device is shut down the added aliases will be deleted too.