From: Mike Williams (ccie2be@swbell.net)
Date: Tue Jun 10 2003 - 23:13:46 GMT-3
Well, certainly all data is encapsulated....... At Layer 4, then Layer
3, then Layer 2......... But I think this requirement (since it was
speaking of a switchport) was referring to trunked encapsulations.
Here's why: On an ethernet switchport, so you EXPECT (and would reject
anything not formatted as) valid ethernet frames (with IP, etc
encapsulated data in it). So it's obvious the requirement isn't asking
you to drop ALL ethernet frames. Since we ruled that out, we can move
on. Switchports (unless configured as L3, and there was no mention of
this being a L3 port) don't deal with Layer 3 and up, that limites us to
considering other encapsulations at Layer 2. I would think, since
ruling out Layer 3 and up, and actual ethernet framing, that leaves us
considering what the requirement means by "encapsulated". Well, dot1q
frames are encapsulated literally. Although technically ISL isn't an
encapsulation (since it's simply a header stuck on the front of the
ethernet frames), you still use the 'trunk encapsulation' command to
configure it. Since using 'switchport mode access' fulfills the
requirement to drop encapsulated frames, it seems like the best choice.
It would make sense that when the requirement says "drop all
encapsulated frames" it's referring to trunked frames.
Mike W.
-----Original Message-----
From: phase90 [mailto:phase90@comcast.net]
Sent: Tuesday, June 10, 2003 8:11 PM
To: Mike Williams; ccielab@groupstudy.com
Subject: Re: 3550 Question
Is not the data still encapsulated?!?!?
Jerry
----- Original Message -----
From: "Mike Williams" <ccie2be@swbell.net>
To: "'phase90'" <phase90@comcast.net>; <ccielab@groupstudy.com>
Sent: Tuesday, June 10, 2003 10:45 AM
Subject: RE: 3550 Question
> switchport mode access
>
> This will make the port ignore (i.e. drop) any dot1q or ISL frames.
>
> Mike W.
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
> Of phase90
> Sent: Monday, June 09, 2003 10:06 PM
> To: Jim Phillipo; ccielab@groupstudy.com
> Subject: Re: 3550 Question
>
>
> Does this thing have a punch-line or what?
>
> I give up how?
>
>
> Jerry
> ----- Original Message -----
> From: "Jim Phillipo" <jim.phillipo@guardent.com>
> To: <ccielab@groupstudy.com>
> Sent: Monday, June 09, 2003 8:52 PM
> Subject: 3550 Question
>
>
> > How is a port configured to drop all encapsulated frames ?
> >
> > Jim Phillipo, CCNP, CCDP
> > Sr. Internetworking Engineer
> > W: 401.456.1821 F: 401.456.0599 M: 508.982.8923
> > 90 Royal Little Drive, Providence, RI 02904 www.guardent.com
> > _____________________________________________________
> > G U A R D E N T
> > Security | Privacy | Data Protection
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