Re: L2 Ethertype mac acl

From: Sean.Zimmerman@clubcorp.com
Date: Thu Apr 26 2007 - 17:03:34 ART


You can also see the ethertype using the following debug:

debug spann switch tx
debug spann switch tx decode

Apr 24 14:21:26.457: STP SW: TX: : 0180.c200.0000<-000f.8ff5.a1c4 type/len
006A
Apr 24 14:21:26.457: encap SAP linktype ieee-st vlan 99 len 120 on v99
Fa0/4
--------> Apr 24 14:21:26.457: 42 42 03 SPAN
Apr 24 14:21:26.457: CFG P:0000 V:03 T:02 F:3C R:0001 000c.db6c.fe00
00035B6
0
Apr 24 14:21:26.457: B:8000 000f.8ff5.a1c0 80.04 A:0200 M:1400 H:0200
F:0F00
    00 00 00 40 00 00 00 00 00 00 00 00 00 00 00 00
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    00 00 00 00 00 00 33 CB 0F 88 A4 33 62 B8 DB E0
    61 3D 5D 34 B4 F7 80 00 00 0F 8F F5 A1 C0 00 00
    00 00 14 00

Sean

"Ronnie Angello" <ronnie.angello@gmail.com>
Sent by: nobody@groupstudy.com
04/26/2007 06:01 AM
Please respond to
"Ronnie Angello" <ronnie.angello@gmail.com>

To
dampened <cheechew@hotmail.com>
cc
"Cisco certification" <ccielab@groupstudy.com>
Subject
Re: L2 Ethertype mac acl

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.
> >
> >



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