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4. How many aliases can Linux handle

Linux 2.0 handle 256 aliases per device. Since Linux 2.0.31 there is a soft limit on the kernel table used to store the aliases. The limit is set to 256 at boot time. This limit may be change by writing a new value in the file

        /proc/sys/net/core/net_alias_max
        

But there is a small catch: This new limit only comes in action when you set the first alias of a device. If there is already some IP alias on a network device, they will have to be unset. When there is no aliases on a device, the table is deleted and it will be recreated with the new limit the next time you set the aliases.

Linuxconf handles all this for you and will unset some aliases before attempting to grow the table. Some messages are sent to the log explaining this.

So linux can handle a lot of aliases.


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