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Catalyst 2950 Desktop Switch Software Configuration Guide
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Chapter 15 Configuring VTP
Configuring VTP

VTP Configuration Guidelines

These sec tions descr ibe guid elines you should fol low when implem entin g VTP in your ne twork.

Domain Names

When co nfiguring VTP f or the first tim e, y ou mu st always a ssign a do main n am e. You must con figure
all switches in the VTP domain with the same domain name. Switches in VTP transparent mode do not
exchange VTP me ssages with oth er switches, and you do not ne ed to configure a V TP domain name
for them.
Note If NVRAM and DRAM storage is sufficient, all switches in a VTP domain should be in VTP server
mode.
Caution Do not configure a VTP domain if all switches are operating in VTP client mode. If you configure the
domain, it is im possible to make changes to the VLAN conf igura tion of that domain. Ma ke sure that yo u
configure at leas t one sw itch i n the V TP domai n for VT P ser ver mode.

Passwords

You can co nfigure a password for t he VT P dom ain , but it is no t requi red. If you do c onfigure a do mai n
password, all dom ain switche s must share the same passwor d and you mus t configure the password on
each switch in the management domain. Switches without a password or with the wrong password reject
VTP ad vert isem ents.
If you configure a VTP password for a domain, a switch that is booted without a VTP configuration does
not accep t VTP adve rtisements until you co nfig ure it with the co rrect passwor d. After the conf iguratio n,
the switch accepts the next VTP advertisement that uses the same password and domain name in the
adver ti s em en t.
If you are adding a new switch to an existing network with VTP capability, the new switch learns the
domain name only after the applica ble password has bee n configured on it.
Caution When you configure a VTP domain password, the management domain does not function properly if you
do not assig n a manage ment domai n password to each sw itch in the dom ain.

Upgrading from Previous Software Releases

When you upgrade from an IOS software versi on that supports VLA Ns but does not support V TP, such
as Release 12.0(5.1)WC, to a version that does support VTP, ports that belong to a VLAN retain their
VLAN membership, and VTP enters transparent mode. The domain name becomes UPGRADE, and
VTP does n ot prop aga te the VLA N co nfiguration to o t her sw itc hes.
If you want t he switch to propagat e VLAN configuration informatio n to other switches a nd to learn t he
VLANs ena ble d o n the net work, you m ust c onfigure the s wit ch w it h th e corr ec t d oma in na me a nd
domain passwo rd and chang e the VTP mode to VTP ser ver.