Two Doubts

Hi
I have 2 doubts -

1)If nothing is mentioned in the show running-config output as to what encapsulation the router is using ,then can it be taken to be HDLC by default?
Is there any command to find out what encapsulation type a point to point router is using apart from the "show running-config" command?

2)If the output of "show running-config" shows -
Serial0/0/0 is up,line protocol is down
Can it be a due to a problem in clock-rate?

3) Can a serial line with a missing clock rate command connected point-to-point to another router causes an effect on the line or protocol status?
I mean does clock rate effect the line status and protocol status?

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Comments

hitmen

1) show int fax/x and search encapsulation

2) could be clock rate, interface set to passive, hello-dead dont match,... a lot of scenarios (any L2 problems)

3) default clock rate will be used

draught

1. HDLC is default. Wrong, on the show interfaces command. Use the show controllers command to see the clock rate.

2.That's going to be variable. A quick way to check is to use the show controllers command and look near top line of the serial interface. That will show if it's DTE or DCE and of the course the issue could be encapsulation as well.

3.Depends on if it's the DCE or DTE side of the connection. Hitman is correct that the clock rate is auto set on modern routers but for a test question that's not likely going to be the case...

Having no clock rate on the DCE interface will cause the line protocol to go down.

urvi

Hi
I found that with no clock rate given both line and protocol status was down!
As soon as I gave the clock rate on DCE end both status changed to up!

iamme4eva

draught wrote: »

Having no clock rate on the DCE interface will cause the line protocol to go down.

That is what draught said.

Well done for labbing it though - that really is the best way to increase your understanding and experience of these things.