From: WorkerBee (ciscobee@gmail.com)
Date: Sat Jan 12 2008 - 23:30:43 ARST
Hi Tarun,
You give me the answer that I am looking for.
I have seen some older config with manual trunk configuration and some
newer config
with switchport voice command. You indeed shine a light on the difference here.
Can you elaborate why changing from manual trunk to access port
reduces STP processing?
Access port itself also run STP instance. If VTP pruning is enabled on
the port, what really
makes the Cat6K cpu so high?
Thanks for your input.
On Jan 13, 2008 12:20 AM, Tarun Pahuja <pahujat@gmail.com> wrote:
> WorkerBee,
> As mentioned in the previous posts both solutions will
> work. One would be the optimal one and the other could increase the CPU load
> on the switch. If prepairing for the CCIE Lab you should be prepared for
> both as 2007 networkers presentation on CCIE Voice specifically talks about
> it.
>
> In older switches(eg, 3500XL) which did not have the capability to auto
> negotiate the VVID, one had to manual set the trunk on the swich port
> connected to the phone. Newer switches have the capability to auto negotiate
> VVID and hence no need to manual set the trunk.
>
> I still remember receiving a call from one of my clients who was complaining
> that his Cat6500 with Sup2 had 72% CPU utilization after Cisco IP Phone
> deployment. His mistake was that he configured an entire line card using the
> manual trunking method on the cat6500 and added another 100+ STP instances
> causing his CPU utilisation to spike. changing the configuration back to
> Voice vlan and Access Vlan brought it down to 23%.
>
> HTH,
> Tarun
>
>
>
> On 1/7/08, WorkerBee <ciscobee@gmail.com> wrote:
> >
> >
> >
> > Which one is more preferred? I have tested both and it works.
> > The only difference for F0/2, it runs extra STP VLAN 1 instance.
> >
> > It seems that F0/1 is less CPU intensive due to lack of DTP, STP VLAN 1,
> > faster L2 convergence since it is static port.
> >
> > Any comments?
> >
> > Requirement
> > =========
> > Data : Vlan 10
> > Voice : Vlan 110
> >
> >
> > interface FastEthernet0/1
> > switchport access vlan 10
> > switchport mode access
> > switchport voice vlan 110
> > spanning-tree portfast
> > end
> >
> >
> > interface FastEthernet0/2
> > switchport trunk encapsulation dot1q
> > switchport trunk native vlan 10
> > switchport mode trunk
> > switchport voice vlan 110
> > spanning-tree portfast
> > end
> >
> >
> > _______________________________________________________________________
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> > http://www.groupstudy.com/list/CCIELab.html
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