Cisco CCNA mock exam questions sample test – Question 57

.Which type of Category 5 unshielded twisted-pair (UTP) cable is used to work as a trunk between two switches?

A. RJ-45 straight-through
B. RJ-41 crossover
C. RJ-11 straight-through
D. RJ-45 crossover

Correct Answer: D

Explanation:
An RJ-45 crossover cable connects two switches. To act as a trunk a trunking protocol such as ISL or 802.1q must be configured on the link. . A trunk is a connection between two
switches that is used to carry traffic from multiple VLANs.
In general, the rule to follow when choosing between a straight-through and a crossover cable is:
When connecting like devices (i.e. router to router, switch to switch), use a crossover cable.
When connecting dissimilar devices (i.e. switch to router), use a straight-through cable.
The one exception to this rule is when connecting a computer NIC to a router, in which case a crossover cable is used. Be aware, however, that many devices, including network
cards in computers, now have the ability to sense automatically when they are connected to a like device and adapt to the connection, making crossover cables unnecessary in those
situations.
You should not choose an RJ-45 straight-through cable. The cable type to be used depends on the circuit connection of the hardware. To connect two switches, a crossover cable is
required. The difference between a straight-through cable and a crossover cable lies in the location of the wire termination on the two ends of an RJ-45 cable. If the UTP cable wire
connects Pin 1 of one side to Pin 1 of other side and Pin 2 to 2 through all eight pins of the RJ 45 connector, the cable is said to be straight-through. On the other hand, if Pin 1 of one
side of an RJ-45 cable connects to Pin 3 of the other end, and Pin 2 connects to Pin 6 of the other end, it is known as a crossover cable. A straight-through cable is used to connect a
computer’s network interface card (NIC) to a hub or switch.
You should not choose an RJ-41 crossover cable. RJ-41 is a single-line universal data jack normally associated with fixed-loss loop (FLL) or programmed (P) modems. It is not used
between switches.
You should not choose an RJ-11 straight-through cable type. RJ-11 UTP cables have four pins and are used to connect voice instruments. RJ-11 UTP cables are not intended for
connecting computers and transferring data. They are commonly used for telephones and modems.
Note: Cisco switches have an auto-mdix feature that notices when the wrong cabling pinouts are used, and readjusts the switch’s logic so that the cable will work.
Objective:
Network Fundamentals
Sub-Objective:
Select the appropriate cabling type based on implementation requirements
References:
Cisco Documentation > Internetwork Design Guide > Designing Switched LAN Internetworks > Technologies for Building Switched LAN Internetworks
Cisco > Troubleshooting Technotes > Cisco 7000 Series Routers > Cabling Guide for Console and AUX Ports > Types of RJ-45 Cabling