From: Michael Snyder (msnyder@xxxxxxx)
Date: Wed Aug 29 2001 - 12:55:42 GMT-3
Chris, to tell the truth, I don't know. But going by the following list
below
42 IEEE 802.1 Bridge Spanning Tree Protocol
I would assume that BPDU's would use sap 0x42.
Going by this list, I also think the arp protocol uses sap 0x98.
I do think you are right about the addresses, Have see those in my sniffer
program.
Lets turn this question around, Since we know all LLC1 and LLC2 frames have
saps, is a BPDU a LLC frame?
I think because it's Ethernet or tokenring it has to be.
Of course this wouldn't be the first time I was completely wrong.
For all I know not all LLC frames have saps or type codes. CDP comes to
mind.
Help!!! Someone please fill in these large holes of nothingness of my
knowledge.
Do these layer two & a half, protocols (cdp, bpdu, arp) have type-codes, llc
formats, saps?
00 Null LSAP
02 Individual LLC Sublayer Management Function
03 Group LLC Sublayer Management Function
04 IBM SNA Path Control (individual)
05 IBM SNA Path Control (group)
06 ARPANET Internet Protocol (IP)
08 SNA
0C SNA
0E PROWAY (IEC955) Network Management & Initialization
18 Texas Instruments
42 IEEE 802.1 Bridge Spanning Tree Protocol
4E EIA RS-511 Manufacturing Message Service
7E ISO 8208 (X.25 over IEEE 802.2 Type 2 LLC)
80 Xerox Network Systems (XNS)
86 Nestar
8E PROWAY (IEC 955) Active Station List Maintenance
98 ARPANET Address Resolution Protocol (ARP)
BC Banyan VINES
AA SubNetwork Access Protocol (SNAP)
E0 Novell NetWare
F0 IBM NetBIOS
F4 IBM LAN Management (individual)
F5 IBM LAN Management (group)
F8 IBM Remote Program Load (RPL)
FA Ungermann-Bass
FE ISO Network Layer Protocol
FF Global LSAP
----- Original Message -----
From: "Burnham, Chris" <chris.burnham@delphis.net>
To: "'Michael Snyder'" <msnyder@ldd.net>; <cisco@groupstudy.com>
Sent: Wednesday, August 29, 2001 3:19 AM
Subject: RE: BPDUs [7:17607]
> I diasagree,
> I understood that the BPDU has it's own frame format ..the
> frame format depends on what type of spanning tree is configured.There is
no
> concept of a SAP field.
>
> Destination Address
> The Destination Address field indicates the destination address as
specified
> in the Bridge Group Address table. For IEEE Spanning-Tree Protocol BPDU
> frames, the address is 0x800143000000. For IBM Spanning-Tree Protocol BPDU
> frames, the address is 0xC00000000100. For Cisco Spanning-Tree Protocol
BPDU
> frames, the address is 0x800778020200.
>
> Source Address
> The Source Address field indicates the base MAC address used by the
switch.
> For Cisco Spanning-Tree Protocol BPDU frames, the multicast bit is set to
> indicate the presence of a RIF in the header.
>
>
>
> -----Original Message-----
> From: Michael Snyder [mailto:msnyder@ldd.net]
> Sent: 29 August 2001 04:59
> To: cisco@groupstudy.com
> Subject: Re: BPDUs [7:17607]
>
>
> Layer two broadcast.
>
> What Sap does it use?
>
>
> ""Christopher Supino"" wrote in message
> news:200108290103.VAA22560@groupstudy.com...
> > All ,
> >
> > I came across this question while studying: How are BPDU's propagated
> > amongst switches? Broadcast, multicast, or unicast? Anyone have an
> > explanation?
> >
> > Christopher Supino
> > CCNP, CCDP, MCSE, CNA5, ASE
> > Senior System Engineer
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