<s>
VLAN	B-Protocol
Trunking	I-Protocol
Protocol	I-Protocol
(	O
VTP	B-Protocol
)	O
is	O
a	O
Cisco	O
proprietary	O
protocol	O
that	O
propagates	O
the	O
definition	O
of	O
Virtual	B-General_Concept
Local	I-General_Concept
Area	I-General_Concept
Networks	I-General_Concept
(	O
VLAN	B-General_Concept
)	O
on	O
the	O
whole	O
local	O
area	O
network	O
.	O
</s>
<s>
To	O
do	O
this	O
,	O
VTP	B-Protocol
carries	O
VLAN	B-General_Concept
information	O
to	O
all	O
the	O
switches	O
in	O
a	O
VTP	B-Protocol
domain	O
.	O
</s>
<s>
VTP	B-Protocol
advertisements	O
can	O
be	O
sent	O
over	O
802.1Q	O
,	O
and	O
ISL	B-Protocol
trunks	O
.	O
</s>
<s>
VTP	B-Protocol
is	O
available	O
on	O
most	O
of	O
the	O
Cisco	B-Device
Catalyst	I-Device
Family	O
products	O
.	O
</s>
<s>
Using	O
VTP	B-Protocol
,	O
each	O
Catalyst	B-Device
Family	O
Switch	O
advertises	O
the	O
following	O
on	O
its	O
trunk	O
ports	O
:	O
</s>
<s>
There	O
are	O
three	O
versions	O
of	O
VTP	B-Protocol
,	O
namely	O
version	O
1	O
,	O
version	O
2	O
,	O
version	O
3	O
.	O
</s>
<s>
On	O
Cisco	O
Devices	O
,	O
VTP	B-Protocol
(	O
VLAN	B-Protocol
Trunking	I-Protocol
Protocol	I-Protocol
)	O
maintains	O
VLAN	B-General_Concept
configuration	O
consistency	O
across	O
a	O
single	O
Layer	O
2	O
network	O
.	O
</s>
<s>
VTP	B-Protocol
uses	O
Layer	O
2	O
frames	O
to	O
manage	O
the	O
addition	O
,	O
deletion	O
,	O
and	O
renaming	O
of	O
VLANs	B-General_Concept
from	O
switches	O
in	O
the	O
VTP	B-Protocol
client	O
mode	O
.	O
</s>
<s>
VTP	B-Protocol
is	O
responsible	O
for	O
synchronizing	O
VLAN	B-General_Concept
information	O
within	O
a	O
VTP	B-Protocol
domain	O
and	O
reduces	O
the	O
need	O
to	O
configure	O
the	O
same	O
VLAN	B-General_Concept
information	O
on	O
each	O
switch	O
thereby	O
minimizing	O
the	O
possibility	O
of	O
configuration	O
inconsistencies	O
that	O
arise	O
when	O
changes	O
are	O
made	O
.	O
</s>
<s>
VTP	B-Protocol
provides	O
the	O
following	O
benefits	O
:	O
</s>
<s>
When	O
a	O
new	O
switch	O
is	O
added	O
to	O
the	O
network	O
,	O
by	O
default	O
it	O
is	O
configured	O
with	O
no	O
VTP	B-Protocol
domain	O
name	O
or	O
password	O
,	O
but	O
in	O
VTP	B-Protocol
server	O
mode	O
.	O
</s>
<s>
If	O
no	O
VTP	B-Protocol
Domain	O
Name	O
has	O
been	O
configured	O
,	O
it	O
assumes	O
the	O
one	O
from	O
the	O
first	O
VTP	B-Protocol
packet	O
it	O
receives	O
.	O
</s>
<s>
Since	O
a	O
new	O
switch	O
has	O
a	O
VTP	B-Protocol
configuration	O
revision	O
of	O
0	O
,	O
it	O
will	O
accept	O
any	O
revision	O
number	O
as	O
newer	O
and	O
overwrite	O
its	O
VLAN	B-General_Concept
information	O
if	O
the	O
VTP	B-Protocol
passwords	O
match	O
.	O
</s>
<s>
However	O
,	O
if	O
you	O
were	O
to	O
accidentally	O
connect	O
a	O
switch	O
to	O
the	O
network	O
with	O
the	O
correct	O
VTP	B-Protocol
domain	O
name	O
and	O
password	O
but	O
a	O
higher	O
VTP	B-Protocol
revision	O
number	O
than	O
what	O
the	O
network	O
currently	O
has	O
(	O
such	O
as	O
a	O
switch	O
that	O
had	O
been	O
removed	O
from	O
the	O
network	O
for	O
maintenance	O
and	O
returned	O
with	O
its	O
VLAN	B-General_Concept
information	O
deleted	O
)	O
then	O
the	O
entire	O
VTP	B-Protocol
Domain	O
would	O
adopt	O
the	O
VLAN	B-General_Concept
configuration	O
of	O
the	O
new	O
switch	O
which	O
is	O
likely	O
to	O
cause	O
loss	O
of	O
VLAN	B-General_Concept
information	O
on	O
all	O
switches	O
in	O
the	O
VTP	B-Protocol
Domain	O
,	O
leading	O
to	O
failures	O
on	O
the	O
network	O
.	O
</s>
<s>
Since	O
Cisco	O
switches	O
maintain	O
VTP	B-Protocol
configuration	O
information	O
separately	O
from	O
the	O
normal	O
configuration	O
,	O
and	O
since	O
this	O
particular	O
issue	O
occurs	O
so	O
frequently	O
,	O
it	O
has	O
become	O
known	O
colloquially	O
as	O
the	O
"	O
VTP	B-Protocol
Bomb	O
"	O
.	O
</s>
<s>
Before	O
creating	O
VLANs	B-General_Concept
on	O
the	O
switch	O
that	O
will	O
propagate	O
via	O
VTP	B-Protocol
,	O
a	O
VTP	B-Protocol
domain	O
must	O
first	O
be	O
set	O
up	O
.	O
</s>
<s>
A	O
VTP	B-Protocol
domain	O
for	O
a	O
network	O
is	O
a	O
set	O
of	O
all	O
contiguously	O
trunked	O
switches	O
with	O
the	O
matching	O
VTP	B-Protocol
settings	O
(	O
domain	O
name	O
,	O
password	O
and	O
VTP	B-Protocol
version	O
)	O
.	O
</s>
<s>
All	O
switches	O
in	O
the	O
same	O
VTP	B-Protocol
domain	O
share	O
their	O
VLAN	B-General_Concept
information	O
with	O
each	O
other	O
,	O
and	O
a	O
switch	O
can	O
participate	O
in	O
only	O
one	O
VTP	B-Protocol
management	O
domain	O
.	O
</s>
<s>
Switches	O
in	O
different	O
domains	O
do	O
not	O
share	O
VTP	B-Protocol
information	O
.	O
</s>
<s>
Non-matching	O
VTP	B-Protocol
settings	O
might	O
result	O
in	O
issues	O
in	O
negotiating	O
VLAN	B-General_Concept
trunks	O
,	O
port-channels	O
or	O
Virtual	O
Port	O
Channels	O
.	O
</s>
