Using WiFi port as redundant link

I want to use WiFi port of my server as redundant link for copper connection to my home DSL router.
My router if SAGEM 2704 with very limited functionality.
So practically the only possibility is to configure something on the server.
Is it possible to use WiFi for redundancy. If so, what I have to implement on my server?

Answers:

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Method 1

You’re looking for bonding. This driver is intended for (surprise!) bonding individual links to one logical link. Several modes are supported, one of them is fail-over mode (you have one primary link, in your case wired ethernet, and several fail-over links, which take over when the primary link fails).

What you’ll need is CONFIG_BONDING enabled in the kernel. With this enabled (and the appropriate module bonding loaded if built as module) can do the following:

1. Create a bonding interface:

   # echo +bond0 > /sys/class/net/bonding_masters

2. Set active-backup mode (fail-over):

   # echo active-backup > /sys/class/net/bond0/bonding/mode

3. Add interfaces to the bonding device:

   # echo +eth0 >  /sys/class/net/bond0/bonding/slaves
   # echo +wlan0 > /sys/class/net/bond0/bonding/slaves

4. Make eth0 the primary interface:

   # echo eth0 > /sys/class/net/bond0/bonding/master

5. Enable link monitoring (periodically test for link availability every second):

   # echo 1000 > /sys/class/net/bond0/bonding/miimon

6. Use bond0 as network interface (eth0 and wlan0 don’t need any further configuration: IP addresses et al are configured on bond0 now).

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0