What is the problem?

After configuring new data VLANs 1020 through 1030 on the VTP server, a network engineer notices that none of the VTP clients are receiving the updates. What is
the problem?

A.
The VTP server must be reloaded.

B.
The VTP version number must be set to version 3.

C.
After each update to the VTP server, it takes up to 4 hours propagate.

D.
VTP must be stopped and restarted on the server.

E.
Another switch in the domain has a higher revision number than the server.

Explanation:
VTP version 3 supports these features that are not supported in version 1 or version 2:
·Enhanced authentication–You can configure the authentication as hidden or secret. When hidden, the secret key from the password string is saved in the VLAN
database file, but it does not appear in plain text in the configuration. Instead, the key associated with the password is saved in hexadecimal format in the running
configuration. You must reenter the password if you enter a takeover command in the domain. When you enter the secret keyword, you can directly configure the
password secret key.
·Support for extended range VLAN (VLANs 1006 to 4094) database propagation. VTP

versions 1 and 2 propagate only VLANs 1 to 1005. If extended VLANs are configured, you cannot convert from VTP version 3 to version 1 or 2.

http://www.cisco.com/en/US/docs/switches/lan/catalyst3560/software/release/12.2_52_se/configur ation/guide/swvtp.html#wp1316856