Refer to the exhibit.
The show interfaces serial 0/1 command was issued on the R10-1 router. Based on the output
displayed which statement is correct?
A.
The cable connected to the serial 0/1 interface of the R10-1 router is a DTE cable.
B.
The R10-1 router can ping the router interface connected to the serial 0/1 interface.
C.
The clock rate used for interface serial 0/1 of the R10-1 router is 1,544,000 bits per second.
D.
The CSU used with the serial 0/1 interface of the R10-1 router has lost connection to the service
provider.
E.
The interface of the remote router connected to the serial 0/1 interface of the R10-1 router is
using the default serial interface encapsulation.
Explanation:
Cisco High-Level Data Link Controller (HDLC) is the Cisco proprietary protocol for Cisco HDLC is the
default encapsulation type for the serial interfaces.
Crappy explanation. There is no way to confirm any of the other answers.
E is correct because we can see that the interface is up/up. If the interface was up/down, it would indicate that there is something connected and that the router is sensing bits on the wire, but that either clocking is not set or that a different type of layer 2 encapsulation is being used. Because the link is up/up and the show interface output states that the layer 2 method is HDLC, we can safely assume that the remote side of the connection is also using HDLC. HDLC is the cisco default layer 2 encapsulation method. The non-cisco default, vendor inter-operable method of encapsulation is PPP.
Layer 2 is up, so we know that HDLC is the encapsulation setting on the other interface and the packets received confirm this for answer E.