projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 735dadf8 TH |
1 | .. SPDX-License-Identifier: GPL-2.0 |
| 2 | ||
| 3 | =========== | |
| 4 | IP-Aliasing | |
| 5 | =========== | |
| 6 | ||
| 7 | IP-aliases are an obsolete way to manage multiple IP-addresses/masks | |
| 8 | per interface. Newer tools such as iproute2 support multiple | |
| 9 | address/prefixes per interface, but aliases are still supported | |
| 10 | for backwards compatibility. | |
| 11 | ||
| 12 | An alias is formed by adding a colon and a string when running ifconfig. | |
| 13 | This string is usually numeric, but this is not a must. | |
| 14 | ||
| 15 | ||
| 16 | Alias creation | |
| 17 | ============== | |
| 18 | ||
| 19 | Alias creation is done by 'magic' interface naming: eg. to create a | |
| 20 | 200.1.1.1 alias for eth0 ... | |
| 21 | :: | |
| 22 | ||
| 23 | # ifconfig eth0:0 200.1.1.1 etc,etc.... | |
| 24 | ~~ -> request alias #0 creation (if not yet exists) for eth0 | |
| 25 | ||
| 26 | The corresponding route is also set up by this command. Please note: | |
| 27 | The route always points to the base interface. | |
| 28 | ||
| 29 | ||
| 30 | Alias deletion | |
| 31 | ============== | |
| 32 | ||
| 33 | The alias is removed by shutting the alias down:: | |
| 34 | ||
| 35 | # ifconfig eth0:0 down | |
| 36 | ~~~~~~~~~~ -> will delete alias | |
| 37 | ||
| 38 | ||
| 39 | Alias (re-)configuring | |
| 40 | ====================== | |
| 41 | ||
| 42 | Aliases are not real devices, but programs should be able to configure | |
| 43 | and refer to them as usual (ifconfig, route, etc). | |
| 44 | ||
| 45 | ||
| 46 | Relationship with main device | |
| 47 | ============================= | |
| 48 | ||
| 49 | If the base device is shut down the added aliases will be deleted too. |