What does HWaddr value of 00-00-00 .... would mean?

Question

I have a raspberry-pi (border router gateway) ordered from silicon labs. It has a USB which implements thread-protocol. The usb is connected to the raspberry-pi. When I do ifconfig on the terminal, I get this output for the tun0 interface.

 tun0 Link encap:UNSPEC  HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
      inet6 addr: fe80::222:a300:11:60e2/64 Scope:Link
      inet6 addr: fd01::3b25:d835:9e0d:3109/64 Scope:Global
      inet6 addr: fe91::222:a300:11:60e2/64 Scope:Link
      inet6 addr: aaaa::1508:3a81:da7c:ec0b/64 Scope:Global
      inet6 addr: fe90::222:a300:11:60e2/64 Scope:Link
      UP DEBUG POINTOPOINT RUNNING  MTU:1500  Metric:1
      RX packets:0 errors:0 dropped:0 overruns:0 frame:0
      TX packets:6 errors:0 dropped:0 overruns:0 carrier:0
      collisions:0 txqueuelen:500
      RX bytes:0 (0.0 B)  TX bytes:736 (736.0 B)

What does this output mean? Specifically I want to understand the output for HWaddr....

Solution

When you see HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 in the output of ifconfig tun0 it simply means that this is a virtual interface. Since this isn't an actual piece of hardware it doesn't have a hardware address.

Even for a virtual interface it is possible to make up a hardware address. However that is usually only needed for virtual Ethernet interfaces. For a tun device it is generally not needed, which is why it is left as all zeros.

Comments

[GAD3R]

Run ifup tun0 or ifconfig tun0 up then check it

[theimpatientcoder]

^ I got this o/p on ifup Ignoring unknown interface tun0=tun0.