I have a raspberry Pi with three interfaces eth0 (Ethernet), wlan0 (WiFi), and wwan0 (via a GSM modem)

  1. How can I test if an Internet connection is available via a certain interface? e.g. is my GSM(wwan0) modem connected to the Internet?

  2. If I attempt to run ping www.google.com - How do I know what interface is being used?

  • 1
    Hi there. It looks as if your question would be better suited on a different Stack Exchange site as it is more related to general Linux operation, rather than Raspberry Pi specifics. If you like I can migrate this question to a relevant place?
    – Jivings
    Commented Oct 1, 2014 at 16:13
  • 2
    Good question though - Unix & Linux may be ideal for it.
    – Wilf
    Commented Oct 1, 2014 at 16:22
  • @Morgan - unix.stackexchange.com/questions/158901/…
    – OneGuyInDc
    Commented Oct 3, 2014 at 13:07