tunl0 - "where did you come from cotton eye joe?" :)

[help40]

where did tunl0 come from ? 

is it there by default or .... may be I must dig in my history ?

root@orangepione:/etc/network $ ifconfig -a
eth0      Link encap:Ethernet  HWaddr 6a:xx:xx:xx:xx:xx  (** edited)
          inet addr:192.168.100.3  Bcast:192.168.100.255  Mask:255.255.255.0
          inet6 addr: fe80::68f2:91ff:fef0:4579/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:35677 errors:0 dropped:0 overruns:0 frame:0
          TX packets:22173 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:3139622 (2.9 MiB)  TX bytes:13744564 (13.1 MiB)
          Interrupt:114 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:29 errors:0 dropped:0 overruns:0 frame:0
          TX packets:29 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:2860 (2.7 KiB)  TX bytes:2860 (2.7 KiB)

tunl0     Link encap:IPIP Tunnel  HWaddr   
          NOARP  MTU:1480  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:0 (0.0   TX bytes:0 (0.0