1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

protocol status down

Discussion in 'Routing & Switching' started by p1xels, Jul 12, 2013.

  1. p1xels

    p1xels Bit Poster

    23
    0
    2
    Hi
    Whatever I learnt in ccna till now regarding the line and protocol status made me doubt the answer of this question which goes like this-
    1.JPG



    A network technician is unable to ping from R1 to R2.What will help correct the problem?


    A Ensure that the serial cable is correctly plugged in to the interfaces.

    B Apply the clock rate 56000 configuration command to the serial0/l interface of R1.

    C Configure the serial0/1 interfaces on R1 and R2 with the no shutdown command.

    D Change the address of the serial0/1 interface of R1 to 192.1.1.4.

    E Change the subnet masks of both interfaces to 255.255.255.240.

    I feel the answer should be option B ,since there is no clock rate showing in the output of the "sh int serial 0/1" but since at least there should be a DCE end with clock rate applied.
    The answer that is shown is option A to my disbelief!!
    Can anyone throw some light why option A should be the answer and not B?
     
    Last edited: Jul 12, 2013
  2. Cunningfox

    Cunningfox Byte Poster

    219
    6
    27
    Wish I could but I also think that B is the correct option. I checked to ensure it:

    Output simulated with missing clock rate:

    Code:
    Router(config-if)#do sh int s0/0
    Serial0/0 is up, line protocol is down (disabled)
      Hardware is HD64570
      Internet address is 192.168.1.2/30
      MTU 1500 bytes, BW 128 Kbit, DLY 20000 usec,
         reliability 255/255, txload 1/255, rxload 1/255
      Encapsulation HDLC, loopback not set, keepalive set (10 sec)
    Now watch:

    Code:
    Router(config-if)#clock rate 56000
    Router(config-if)#
    %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0, changed state to up
    
    Router(config-if)#do sh int s0/0
    Serial0/0 is up, line protocol is up (connected)
      Hardware is HD64570
      Internet address is 192.168.1.2/30
      MTU 1500 bytes, BW 128 Kbit, DLY 20000 usec,
         reliability 255/255, txload 1/255, rxload 1/255
      Encapsulation HDLC, loopback not set, keepalive set (10 sec)
    A is wrong because I don't think the port would be up without a link
    C is plain wrong because it would say administratively down (or similar)
    D is plain wrong as it moves one end out of the same subnet, and the issue is below layer 3
    E is plain wrong as this is an incorrect subnet mask, and the issue is below layer 3

    I open myself to being corrected as I don't use serial links much, or ever since I did CCNA, but I think you are bang on here. However, your reasoning is wrong, clock rate is not shown in show interface.
     
    Last edited: Jul 12, 2013
    Certifications: CCNP, CCNA, MCP
    WIP: ??
    p1xels likes this.
  3. p1xels

    p1xels Bit Poster

    23
    0
    2
    Thanks bro for confirmation :)
     

Share This Page

Loading...