This is from Cisco Documentation. "To partition spanning tree protocol (STP) topology for the default VLAN, you can remove VLAN1 from the list of allowed VLANs. Otherwise, VLAN1, which is enabled on all ports by default, will have a very big STP topology, which can result in problems during STP convergence. When you remove VLAN1, all data traffic for VLAN1 on this port is blocked, but the control traffic continues to move on the port. "
CDP , VTP seems cross link , but STP BPDU s are blocked. have to test it Ken. On Thu, May 10, 2012 at 9:49 PM, Bob McCouch <[email protected]> wrote: > So CDP, STP, VTP, etc., do not cross a trunk if you do not allow the native > VLAN? > > I'll have to lab that up, I'm pretty sure that's not the case. > > > On Thu, May 10, 2012 at 12:17 PM, Rob Hoover <[email protected]> wrote: > > > If the trunk is configured for allow, you do have to include the native > > vlan in that statement. > > On May 10, 2012 8:29 AM, "Bob McCouch" <[email protected]> wrote: > > > >> I believe the exception there is L2 control packets (VTP, CDP, STP, DTP, > >> etc) that will all be sent untagged over the link whether the native > VLAN > >> is actually allowed on the trunk or not. > >> > >> Marko, do I have that right? > >> > >> > >> > >> On Thu, May 10, 2012 at 8:33 AM, Rob Hoover <[email protected]> wrote: > >> > >>> You have to list the native VLAN in the allowed statement or the packet > >>> will be dropped. > >>> On May 10, 2012 3:31 AM, "imad Abdallah" <[email protected]> > >>> wrote: > >>> > >>> > > >>> > Hi,I'm bit confused regarding native vlan and trunk allowed vlan. > Let's > >>> > say we have two switches connected via trunk. Both switches have the > >>> > default native vlan (vlan 1). On the trunk between them, we issued > the > >>> > command: swi trun allo vlan 2-100. So the native vlan 1 is not > allowed > >>> on > >>> > the trunk. is it mandatory for the native vlan to be allowed on thee > >>> trunk? > >>> > Do we need to change the native vlan from (1) to any other vlan that > >>> are > >>> > allowed through the trunk? Thanks > >>> > _______________________________________________ > >>> > For more information regarding industry leading CCIE Lab training, > >>> please > >>> > visit www.ipexpert.com > >>> > > >>> > Are you a CCNP or CCIE and looking for a job? Check out > >>> > www.PlatinumPlacement.com <http://www.platinumplacement.com/> > >>> > > >>> > http://onlinestudylist.com/mailman/listinfo/ccie_rs > >>> > > >>> _______________________________________________ > >>> For more information regarding industry leading CCIE Lab training, > >>> please visit www.ipexpert.com > >>> > >>> Are you a CCNP or CCIE and looking for a job? Check out > >>> www.PlatinumPlacement.com <http://www.platinumplacement.com/> > >>> > >>> http://onlinestudylist.com/mailman/listinfo/ccie_rs > >>> > >> > >> > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > > Are you a CCNP or CCIE and looking for a job? Check out > www.PlatinumPlacement.com <http://www.platinumplacement.com/> > > http://onlinestudylist.com/mailman/listinfo/ccie_rs > _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com Are you a CCNP or CCIE and looking for a job? Check out www.PlatinumPlacement.com http://onlinestudylist.com/mailman/listinfo/ccie_rs
