I am trying to make my Pi accessible via SSH regardless of which wireless network it is connected to. For this end I have setup a static IP address to the `wlan0` interface. Problem is that I cannot SSH to the Pi, ping it from other devices or ping anything in the network from the Pi. However, I can browse internet and ping addresses such as www.stackexchange.com from the Pi. 

The problem goes away if I shutdown the `eth0` interface with `sudo ifconfig eth0 down`. Then everything works perfectly. However, `eth0` is back and running after a reboot. How can I direct all traffic to prefer the `wlan0` interface instead of (not connected) ethernet?

I have the model 3b and am running Raspbian Jessie. My network/interfaces file


    auto lo
    iface lo inet loopback
    
    auto eth0
    allow-hotplug eth0
    iface eth0 inet manual
    
    auto wlan0
    allow-hotplug wlan0
    iface wlan0 inet manual
    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

At the end of my dhcpcd.conf I have 

    interface wlan0
    static ip_address=192.168.0.240/24
    static routers=192.168.0.1
    static domain_name_servers=192.168.0.1
and `192.168.0.240` is the address I try to ping/connect to.

When I ping other devices from the Pi while `eth0` is active, I can see it tries to ping from the address of the ethernet, although the cable is not plugged and wifi should be used. This is how I figured to disable it and it seems to be the cause of the problem. Moreover, upon booting I get the message.

> Waiting for network for 110 additional seconds

In a nutshell: Pi seems to use wrong network interface, how to fix?