The only protocol for sure that uses VLAN 1 is VTP. If you block VLAN 1 than VTP will not get trough. The other protocols are using the native vlan (correct me if I'm wrong) and by blocking the native vlan you won't block STP or CDP. To block STP or CDP on an interface you need to use other tools like 'no cdp enable' or 'spanning-tree bpdufilter enable'
-- Regards, Rick Mur CCIE2 #21946 (R&S / Service Provider) Juniper JNCIA-ER & JNCIA-EX MCSA:Messaging, MCSE Sr. Support Engineer – IPexpert, Inc. URL: http://www.IPexpert.com On Thu, Aug 20, 2009 at 1:50 PM, vishal bhugra <[email protected]>wrote: > HI Kim > > If I remember correctly ..STP, BPDU, CDP like things use VLAN 1 to travel > across. Thats the only reason..vlan 1 is made not be pruned. > > Guys please correct me If I am wrong. > > Thanks > > On Thu, Aug 20, 2009 at 4:51 PM, Kim Pedersen <[email protected]> wrote: > >> Hi All, >> >> I have a question regarding the native vlan in dot1q. Frames comming >> from the vlan that is choosen as the native vlan is not tagged across >> the trunk. I can manually set the native vlan to be, say 200. I can then >> also say that i only want to allow vlan 250 to cross the trunk. I was >> under the impression that stuff like CDP used the native vlan across >> trunks, but if it is manually pruned (by not allowing it), why does it >> still work? >> >> Am I wrong in that CDP does not use the native vlan? >> >> What I was trying to do was to follow Cisco's guidelines as to not use >> the native vlan 1. However, since VTP cant prune vlan 1, I was doing it >> manually and came up with this thought... >> >> Hopefully someone can clear it up for me. >> >> Thanks >> >> Sincerely, >> Kim Pedersen >> >> -- >> >> // Freedom Matters >> // Follow my progress on: http://kpjungle.wordpress.com >> >> _______________________________________________ >> For more information regarding industry leading CCIE Lab training, please >> visit www.ipexpert.com >> > > > > -- > Thanks®ards > > Vishal > +91-997111066 > Best way to predict the future ..... is to create it > > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > >
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