If you were to configure an ISL Ethernet trunk between two Cisco switches, named R1 and
R2, what would you have to include at the end of the link for the trunk to operate correctly?
(Select two)

A.
An identical VTP mode.

B.
An identical speed/duplex.

C.
An identical trunk negotiation parameter.

D.
An identical trunk encapsulation parameter.

Explanation:
In order for a trunk to be operational, the speed and duplex settings must match at each end
of the trunk, and both switches must use the same trunking encapsulation (802.1Q or ISL).
Incorrect Answers:
A: It is common for switches to have trunk links operating, while the VTP modes differ. For
example, a switch configured with VTP mode server can have a trunk connected to a switch
with VTP mode client.
C: This is incorrect, as there are a number of configurations that are supported where the
trunk negotiation parameters differ between switches. For example, switch R1 could have
the trunk configured for “on” while switch R2 could have the switch trunk configured for
“desirable” and the trunk would be operational.