From: tycampbell@comcast.net
Date: Tue Aug 10 2004 - 10:11:56 GMT-3
Tim,
I haven't tried it with the trunk option on the portfast, I don't believe it is needed.
I am leaning this way because when you configure the voice vlan on the interface, the interface is put into the portfast state automatically, without the "trunk" keyword. I think I could use a little more resaech into this myself.
Could it be that when trunking, the portfast command is only applied, or used by the voice vlan, and not the access vlan or native vlan ?
What I found on the DOC CD is very interesting
"To enable Port Fast on trunk ports, you must use the spanning-tree portfast trunk interface configuration command. The spanning-tree portfast command will not work on trunk ports."
I cannot find any reference to spanning-tree portfast under configuring voice vlan guide for 3550, however I do have a reference to portfast in the IPExpert student guide written by Scott Morris
:-)
-------------- Original message --------------
> Thanks Ty,
>
> Actually, I was asking about the trunk option in the spanning-tree portfast
> [trunk] command.
>
> In your 2 examples, the trunk option doesn't appear after the spanning-tree
> portfast command. Why not? Is that because the port is trunking in any
> case? If so, then why bother to ever include "trunk" in the portfast
> command?
>
> If the trunk option (of portfast command) isn't needed when an IP Phone is
> attached to a port, when is it needed?
>
> Are there any situations where NOT having the trunk option configured will
> cause problems? Or, conversely, are there situations where you MUST have
> the trunk option or you'll have problems.
>
> Actually, I can't think of any reason why the portfast command has a "trunk"
> option. It seems to be completely pointless and only serves to distract
> ccie candidates from more important topics.
>
> What do you think?
>
> Tim
> ----- Original Message -----
> From:
> To: "ccie2be" ; "Group Study"
> Sent: Tuesday, August 10, 2004 8:14 AM
> Subject: Re: spanning-tree portfast trunk
>
>
> > Tim,
> >
> > When doing voice vlan, portfast is automatically configured wether in
> trunk mode or not.
> >
> > here are 2 examples
> >
> > no trunking specified
> > int f0/1
> > switchport trunk encapsulation dot1q
> > switchport voice vlan 105
> > switchport access vlan 106
> > spanning-tree portfast
> >
> > trunking specified
> > int f0/2
> > switchport trunk encapsulation dot1q
> > switchport voice vlan 105
> > switchport mode trunk
> > switchport trunk native vlan 106
> > spanning-tree portfast
> >
> > on the 2nd example, since you are trunking, you should use "switchport
> trunk native vlan" in place of "switchport access vlan". The spanning-tree
> portfast is automatically configured when you configure the voice vlan (I
> believe)
> >
> > I hope that is what you were looking for :-)
> >
> > Ty
> >
> >
> > > Hi guys,
> > >
> > > Is the only time the "trunk" option can be used correctly on above
> command is
> > > when port is connected to an IP Phone?
> > >
> > > Also, if an IP Phone is connected to a port, and span portfast is
> configured
> > > without the trunk option, will that cause a problem or generate an error
> > > message?
> > >
> > > Thanks, Tim
> > >
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