From: Todd, Douglas M. (DTODD@PARTNERS.ORG)
Date: Sat Feb 10 2007 - 01:17:04 ART
I wish to add a comment or two, from my perspective:
VTP allows for the propagation of vlan information, nothing more nothing less.
Spanning-tree (STP) is a completely separate protocol and configuration. You
could have vtp enabled but stp disabled (not a good thing to have stp disabled).
It (vtp) does not assign vlans to interface, or create stp processes or any
thing like that.
You can disable vtp's server/client mode by putting the switch in transparent
mode. This then removes the problems which are inharent to vtp (vtp servers and
versioning, believe me we have had problems here with it, that is why we are in
transparent mode).
As Brian said, vtp domains allow for adminstrative domains. Thus if the domains
don't match you will get the following errors on the switch:
5d06h: %DTP-5-DOMAINMISMATCH: Unable to perform trunk negotiation on port Fa0/13
because of VTP domain mismatch.
5d06h: %DTP-5-DOMAINMISMATCH: Unable to perform trunk negotiation on port Fa0/14
because of VTP domain mismatch.
5d06h: %DTP-5-DOMAINMISMATCH: Unable to perform trunk negotiation on port Fa0/15
because of VTP domain mismatch.
RackSW4#
I believe vtp information will not propegate when the domains don't match, i
could be wrong...
Spanning-tree can be implemented via PVST+ or MST or RSVT. Here is a link for
information:
http://www.cisco.com/univercd/cc/td/doc/product/core/cis7600/ios121_8/swcg/spant
ree.htm#1050594
Now you can have spanning-tree disabled, but still have vtp running. Not a good
idea, but you can do this. However, if using PVST+ there will be one
spanning-tree instance per vlan. VTP does not have anything to do with this,
but, vtp allows you to add, modify, delete vlans based on being
server/transparent.
If you create a vlan, the switch will propagate the vlan via vtp to all other
switches in it's domain (in it's default configuration - no pruning, vtp
domains default..) The switch will create a STP process with a default priority
of 32768 + Extended Sys-ID and there will be an election for whom is the root in
this "vlan". This STP process is then tied to the vlan via the extended sys-id
and the MAC.
I believe to terminate a STP domain you may use a vlan or a L3 boundry? But to
terminate a VTP domain, would require a L3 boundry only, this is assuming we are
not running in transparent mode. If you are running in transparent mode vtp is a
lost cause and you are reliant on manual configuration of everything. Is this a
true assumption?
Cheers!
DMT
-----Original Message-----
From: nobody@groupstudy.com on behalf of Brian McGahan
Sent: Fri 2/9/2007 8:34 PM
To: Capt.Spock; Group Study
Subject: RE: Is Spanning-Treel protocol limited to a VTP domain?
The VTP domain just determines how the administration of VLANs
is handled, it does not determine the broadcast domain. Assuming that
between these switches in different VTP domains you have trunks that
carry common VLANs then yes they will be in the same STP domain. If you
wanted to terminate the STP domain then you could enable layer 3 routing
on the link between the switches instead of running it as a switchport.
HTH,
Brian McGahan, CCIE #8593 (R&S/SP)
bmcgahan@internetworkexpert.com
Internetwork Expert, Inc.
http://www.InternetworkExpert.com
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-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Capt.Spock
Sent: Friday, February 09, 2007 3:12 PM
To: Group Study
Subject: Is Spanning-Treel protocol limited to a VTP domain?
Is Spanning-Treel protocol limited to a VTP domain?
I have two different VTP domains trunked together. There are some VLAN
numbers same on both the side. Now is it possible that Spanning-Tree
selection will cross the VTP domains?
Thanks!
This archive was generated by hypermail 2.1.4 : Thu Mar 01 2007 - 07:38:46 ART