| 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. | |
| o 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. | |
| o Alias deletion. | |
| The alias is removed by shutting the alias down: | |
| # ifconfig eth0:0 down | |
| ~~~~~~~~~~ -> will delete alias | |
| o Alias (re-)configuring | |
| Aliases are not real devices, but programs should be able to configure and | |
| refer to them as usual (ifconfig, route, etc). | |
| o Relationship with main device | |
| If the base device is shut down the added aliases will be deleted | |
| too. |