A little correction on my answer, VTP does not use the Native VLAN :-) Here is what I found regarding the use of VTP and VLAN1: The Case of VLAN 1
You cannot apply VTP pruning to VLANs that need to exist everywhere and that need to be allowed on all switches in the campus, in order to be able to carry VTP, Cisco Discovery Protocol [CDP] traffic, and other control traffic. However, there is a way to limit the extent of VLAN 1. The feature is called VLAN 1 disable on trunk. The feature is available on Catalyst 4500/4000, 5500/5000, and 6500/6000 series switches in CatOS software release 5.4(x) and later. The feature allows you to prune VLAN 1 from a trunk, as you do for any other VLAN. This pruning does not include all the control protocol traffic that is still allowed on the trunk (DTP, PAgP, CDP, VTP, and others). However, the pruning does block all user traffic on that trunk. With this feature, you can keep the VLAN from spanning the entire campus. STP loops are limited in extent, even in VLAN 1. Configure VLAN 1 to be disabled, as you would configure other VLANs to be cleared from the trunk: UDLD uses native VLAN in order to talk to the neighbor. So, in a trunk port, the native VLAN must not be pruned in order for UDLD to work properly. http://www.cisco.com/en/US/tech/tk389/tk689/technologies_tech_note09186a0080890613.shtml Sorry for the confusion. best regards Michel On 25/08/2008, Michel Grossenbacher <[EMAIL PROTECTED]> wrote: > > Hi Mike > Actually VLAN 1 is not pruning-eligible so you can not prune VLAN 1 from a > trunk. However you can remove it from the trunk. > If you remove it from the trunk and change the native VLAN for the trunk, > VTP will then use the new native VLAN for updates. > best regards > > Michel > > > On 25/08/2008, Mike Louis <[EMAIL PROTECTED]> wrote: >> >> List, >> >> I just read in a practice test for an upcoming cert that Vlan 1 is used to >> carry VTP advertisements. However, it is possible to prune vlan 1 from trunk >> links. Will VTP continue to function without Vlan 1 being enabled on the >> link? Has this changed in more recent IOS releases? >> >> Note: This message and any attachments is intended solely for the use of >> the individual or entity to which it is addressed and may contain >> information that is non-public, proprietary, legally privileged, >> confidential, and/or exempt from disclosure. If you are not the intended >> recipient, you are hereby notified that any use, dissemination, >> distribution, or copying of this communication is strictly prohibited. If >> you have received this communication in error, please notify the original >> sender immediately by telephone or return email and destroy or delete this >> message along with any attachments immediately. >> >> _______________________________________________ >> cisco-nsp mailing list [email protected] >> https://puck.nether.net/mailman/listinfo/cisco-nsp >> archive at http://puck.nether.net/pipermail/cisco-nsp/ >> > > _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
