| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | |
| 2 | IP-Aliasing: |
| 3 | ============ |
| 4 | |
| Stephen Hemminger | 58092d1 | 2009-01-29 16:16:31 -0800 | [diff] [blame] | 5 | IP-aliases are an obsolete way to manage multiple IP-addresses/masks |
| 6 | per interface. Newer tools such as iproute2 support multiple |
| 7 | address/prefixes per interface, but aliases are still supported |
| 8 | for backwards compatibility. |
| 9 | |
| 10 | An alias is formed by adding a colon and a string when running ifconfig. |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | This string is usually numeric, but this is not a must. |
| 12 | |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | o Alias creation. |
| 14 | Alias creation is done by 'magic' interface naming: eg. to create a |
| 15 | 200.1.1.1 alias for eth0 ... |
| 16 | |
| 17 | # ifconfig eth0:0 200.1.1.1 etc,etc.... |
| 18 | ~~ -> request alias #0 creation (if not yet exists) for eth0 |
| 19 | |
| 20 | The corresponding route is also set up by this command. |
| 21 | Please note: The route always points to the base interface. |
| 22 | |
| 23 | |
| 24 | o Alias deletion. |
| 25 | The alias is removed by shutting the alias down: |
| 26 | |
| 27 | # ifconfig eth0:0 down |
| 28 | ~~~~~~~~~~ -> will delete alias |
| 29 | |
| 30 | |
| 31 | o Alias (re-)configuring |
| 32 | |
| 33 | Aliases are not real devices, but programs should be able to configure and |
| 34 | refer to them as usual (ifconfig, route, etc). |
| 35 | |
| 36 | |
| 37 | o Relationship with main device |
| 38 | |
| 39 | If the base device is shut down the added aliases will be deleted |
| 40 | too. |