Do VTP clients advertise VLAN info?

[limtohsoon]

Hi Sir,

I have the following scenario:

Two switches, both having the same VTP domain name, configuration revision number equal zero, and are in client modes.

They are initially up and running. Then they are connected via a VLAN trunk. Any chance that one switch will advertise its VLAN info and thus overwrite the other switch's stored VLAN info?

I sort of came across this problem but I can't tell for sure. I understand that switches in VTP client mode will not advertise their VLAN info, but merely listen to and relay VTP info from VTP servers.

Please clear my doubt.

Thank you.

B.Rgds,

Lim TS

[Kevin Dorrell]

In fact, a VTP client will advertise its VLANs, and can overwrite the domain database. The only thing a client does not do is allow you to enter VLANs in the configuration.

Here is a good document. In particular, the flash animation is well worth watching:

http://www.cisco.com/en/US/tech/tk389/tk689/technologies_tech_note09186a0080094c52.shtml

This section is relevant to your question:

http://www.cisco.com/en/US/tech/tk389/tk689/technologies_tech_note09186a0080094c52.shtml#vtp_ts_rec_ins

Kevin Dorrell

Luxembourg

[limtohsoon]

Hi Kevin,

What you said is true. I've done a lab that verifies it.

Thank you.

B.Rgds,

Lim TS

[milan.kulik]

Just one note:

AFAIK, as far as the revision number is the same (zero in your case), the VLAN info received should be ignored.

Only VTP advertisement with HIGHER revision number should overide the VLAN database.

But I haven't tested this feature and wouldn't 100% rely on this fact.

Regards,

Milan