[c-nsp] Mysterious tunnel interfaces

[Ivan]

> I was working on a ISR 1941 with 15.0(1)M2.  I am running DMVPN on it
> and using one tunnel interface.  (Tunnel 1).  No other tunnel
> interfaces are configured on the router.  However when I do "show int
> summary" I get this;
>
> #sh int summary
>
>  *: interface is up
>  IHQ: pkts in input hold queue     IQD: pkts dropped from input queue
>  OHQ: pkts in output hold queue    OQD: pkts dropped from output queue
>  RXBS: rx rate (bits/sec)          RXPS: rx rate (pkts/sec)
>  TXBS: tx rate (bits/sec)          TXPS: tx rate (pkts/sec)
>  TRTL: throttle count
>
>   Interface              IHQ   IQD  OHQ   OQD  RXBS RXPS  TXBS TXPS TRTL
> ------------------------------------------------------------------------
> * GigabitEthernet0/0       0     0    0     0  6000    5  6000    5    0
>   GigabitEthernet0/1       0     0    0     0     0    0     0    0    0
> * Serial0/0/0              0     0    0     0  3000    3  2000    2    0
>   NVI0                     0     0    0     0     0    0     0    0    0
> * Tunnel0                  0     0    0     0     0    0     0    0    0
> * Tunnel1                  0     0    0    10  1000    2  1000    2    0
> * Tunnel2                  0     0    0     0     0    0     0    0    0
> * Tunnel3                  0     0    0     0     0    0     0    0    0
>
> I thought may be something got left behind while I was monkeying
> around in it so I reloaded the router and the tunnel 0,2,3 are still
> there and it says it's up.   None of those interfaces are in the
> startup or running-config.
>
> What is going on here?  My other routers with similar config on a 1841
> with 12.4(15)T* doesn't have this issue.  It doesn't seem to be
> affecting the routing of traffic but it's really bothering me.
>
> -Jay

I have seen similar on ASRs.  From memory I think there were some of the
mystery tunnels and then quite a few more after enabling multicast.. 
Would be great to see an explaination though.

Cheers

Ivan