Default interface state

I'm doing unit 2 of CCNA and have tried some practice MCQs for module 2 (configuring a router). One of the questions asked about the default state of the interfaces. The options included :

down, line protocol down

and

administratively down, line protocol down

I knew that the default was down and guessed the first option but I was wrong.

I have two questions:

Firstly, what's the difference between "down" and "administratively down"?

Secondly, does "line protocol" refer to whether a routing protocol is configured or something else?

Thanks for your time.

Down means the link is down no layer one connection and line protocol down can mean a couple of things. When you see administratively down that means there is a shutdown command on that interface. When you start a router up for the first time the interfaces are administratively down so they have a shutdown command in the configuration. You need to enter the no shutdown command to bring them up.

That's great sp1k3tou, thank you. I didn't know that simply having a cable unplugged could change the report from up to down. I realise that the default setting is down, hence the need to issue no shutdown after configuring.

You mentioned that line protocol down could mean a couple of things - can you elaborate?

Line Protocol is typically issues associated with Layer 2 of the OSI. If you think of the Link Down/Administratively Down as Layer 1 (Phyiscal Layer), Line Protocl is at the Data Link Layer.

I think that an example of this would be on a serial link where there are two different sets of encapsulation configured. i.e. one end could be set to HDLC and the other end could be set to PPP. This could therefore have a Line Protocol issue. Other issues such as timing problems, keep alives, and others

Cheers

Thank you Wayne. We've not got as far as configuring the encapsulation, keep alives etc. on each end of a serial link. I'll bear what you've said in mind for later during the course.