Bad practice Question?

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Is this a bad practice question or am I just no understanding? How could the the dialer interface IP be used on the same router as a tunnel destination? You'll notice I marked answer "B" below as correct, but the practice exam said R4 was just fine.. WHAT? See screenshots..

@Adam-Tyler,

It's the line Tunnel protocol/transport GRE/IP

So when using this tunnel.
On R4, the show interfaces tunnel is reporting what it is seeing as data from the other end. The source is from R2 (source) to R4 (destination).

R2 is to show the same thing as well except that the tunnel source is not matching the R4 source which should be 10.10.10.1 instead of 10.10.1.10.

Yea, still not getting it. How can R4 with a local interface IP'd at 10.10.10.1 (Dialer1) also have a tunnel interface with a configured destination of 10.10.10.1?

Wouldn't the tunnel destination on R4 have to be the IP address of a remote router?

Perhaps the use of PPPoE here changes the game in a way that I am not following?

-Adam

@Adam-Tyler,

It's receiving traffic from the source on it's own dialer interface.

Thanks for sticking with me Ronnie. Maybe the output of the command "show interfaces tunnel 4" and "show run interface tun 4" would be different in this case?

Is the "show interfaces" command showing actual statistics?
and
The "show run int tun 4" command would should a remote ip for destination?

-Adam

@Adam-Tyler,

In the example above it's showing that the interface configuration that is using EIGRP as well as the tunnel configuration.

This is driving my crazy. I still don't get it and I don't understand where my mental block is. I do not understand how it is right that R4 in the above scenario can have a tunnel4 "destination" that is equal to a local interface. Ie Dialer1 IP'd at 10.10.10.1. Unless that local interface being a Dialer changes something? Going crazy over this. not sure where the mental block is.

I created my own lab scenario to test the outputs of "show interface tunnel x".. THE DESTINATION IP IS NOT EQUAL TO THE IP OF A LOCAL INTERFACE. What am I missing!!!? lol.