Learning by Doing: CISCO Certified Network ... - SCN Research

Basic VTP
Objective:
In this lab you will learn the basics of the Virtual Trunking Protocol (VTP). Also you
will learn how and why it is used with switches in networks.
Tools and Materials:
(3) CISCO switch (1900 series)
(3) straight-through cables (st)
(3) Windows PC workstations with Hyperterminal and Ethereal installed
(1) console cable
(3) Crossover cables (xo)
Lab Diagram:
1
bx ax workstation “a”
192.168.1.1/24
ax
bx
1 1
workstation “c”
workstation “b”
192.168.1.3/24 192.168.1.2/24
Background:
Virtual Trunking Protocol (VTP) allows us to control network broadcasts from one
switch leg to another. In our diagram above if we sent a broadcast from workstation B
(for example, ping 192.168.1.255) then each switch and workstation would receive that
broadcast message. Sometimes we may find our networks becoming congested and need
to control those broadcasts a little bit better, especially in Novell networks. VTP is “off”
by default on each port of a switch. This will allow all broadcasts through. If we enable
(by turning VTP “on”) then we will stop ALL broadcasts to that port. It is kind of a
double-edged sword because you cannot really be selective about which broadcasts to
allow through…you can only select all of them. If we enable VTP on the bx port on the
top switch you will stop any broadcasts from reaching workstation c.
Step-By-Step Instructions:
1. Set up and cable the lab as shown. Do not forget to use crossover cables from switch
to switch.
2. Start an Ethereal capture.
3. Ping from b to c.
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