From: Ronnie Angello (ronnie.angello@gmail.com)
Date: Thu Apr 26 2007 - 08:01:07 ART
Sean Z. answered this already. See below...
I used wireshark to capture a MSTP BPDU, and it appears to have the same
DSAP and SSAP as a regular STP BPDU. It uses an STP version number 3 to
signify mst.
Here's the output of the capture:
IEEE 802.3 Ethernet
Destination: Spanning-tree-(for-bridges)_00 (01:80:c2:00:00:00)
Address: Spanning-tree-(for-bridges)_00 (01:80:c2:00:00:00)
.... ...1 .... .... .... .... = IG bit: Group address
(multicast/broadcast)
.... ..0. .... .... .... .... = LG bit: Globally unique address
(factory default)
Source: Cisco_f5:a1:c4 (00:0f:8f:f5:a1:c4)
Address: Cisco_f5:a1:c4 (00:0f:8f:f5:a1:c4)
.... ...0 .... .... .... .... = IG bit: Individual address
(unicast)
.... ..0. .... .... .... .... = LG bit: Globally unique address
(factory default)
Length: 106
Logical-Link Control
DSAP: Spanning Tree BPDU (0x42)
IG Bit: Individual
SSAP: Spanning Tree BPDU (0x42)
CR Bit: Command
Control field: U, func=UI (0x03)
000. 00.. = Command: Unnumbered Information (0x00)
.... ..11 = Frame type: Unnumbered frame (0x03)
Spanning Tree Protocol
Protocol Identifier: Spanning Tree Protocol (0x0000)
Protocol Version Identifier: Multiple Spanning Tree (3)
BPDU Type: Rapid/Multiple Spanning Tree (0x02)
BPDU flags: 0x3c (Forwarding, Learning, Port Role: Designated)
0... .... = Topology Change Acknowledgment: No
.0.. .... = Agreement: No
..1. .... = Forwarding: Yes
...1 .... = Learning: Yes
.... 11.. = Port Role: Designated (3)
.... ..0. = Proposal: No
.... ...0 = Topology Change: No
On 4/25/07, dampened <cheechew@hotmail.com> wrote:
>
> Yes, from iewb lab 11, it pvst should be 0x4242. I can't remember how
> 0x4343 came from.
>
> Any idea about mst ethertype?
>
> This thing really drive me mad !!! Not available in docCD.
>
>
>
> ----- Original Message -----
> *From:* Ronnie Angello <ronnie.angello@gmail.com>
> *To:* dampened <cheechew@hotmail.com>
> *Cc:* Cisco certification <ccielab@groupstudy.com>
> *Sent:* Thursday, April 26, 2007 3:29 AM
> *Subject:* Re: L2 Ethertype mac acl
>
>
> I believe that pvst uses 0x4242, not 0x4343.
>
> Ronnie
>
>
> On 4/23/07, dampened <cheechew@hotmail.com> wrote:
> >
> > Could someone comment the accuracy of my compilation?
> >
> > arp = 0x806 0x0
> > pvst+ = 0xAAAA 0x0
> > pvst = 0x4343 0x0
> > stp = 0x4242 0x0
> > mst = ?
> >
> > Does anyone know what value should be used for MST?
> > Where can I get all this information from DocCD? The one that on the
> > Bridging Command appendix is not complete.
> >
> > _______________________________________________________________________
> > Subscription information may be found at:
> > http://www.groupstudy.com/list/CCIELab.html
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