Which scenario would cause the tunnel interface on a router to show a status of down/down?
A. The source physical interface is in a down/down state
B. The destination router’s physical interface is shut down
C. The shutdown command has been issued on the virtual interface
D. The destination address is missing on the tunnel configuration
I completely agree with Zboy. The question is poorly stated, but if physical source is in shuw down (or down state), then interface tunnel will be up/down. I tested in my environment.
there is no down/down state.
the best answer here is C, which will put the tunnel in administratively down/down state.
Four Different Tunnel States
There are four possible states in which a GRE tunnel interface can be:
1. Up/up – This implies that the tunnel is fully functional and passes traffic. It is both administratively up and it’s protocol is up as well.
2. Administratively down/down – This implies that the interface has been administratively shut down.
3. Up/down – This implies that, even though the tunnel is administratively up, something causes the line protocol on the interface to be down.
4. Reset/down – This is usually a transient state when the tunnel is reset by software. This usually happens when the tunnel is misconfigured with a Next Hop Server (NHS) that is it’s own IP address.
for your reference:
https://www.cisco.com/c/en/us/support/docs/ip/generic-routing-encapsulation-gre/118361-technote-gre-00.html
Nameless one is right. down/down means down hard which means something is physically wrong with the connection thus Layer 1 Physical
If source physical interface is shutdown we have Administratively down/down.
Shouldn’t be C answer?
down/down and Admin down/down are 2 different status.
You’ll have Admin down/down if you shut down the interface manually (shutdown command).
You’ll have down/down if the source physical interface is down.