Foundry NetIron M2404C and M2404F Metro Access Switches
Configuring MSTP (Rev. 03)
Overview
© 2008 Foundry Networks, Inc
Page 17 of 70
Field name
Value
Note
Protocol version
Identifier
03
-
BPDU type
02
-
CIST Flags
68
-
CIST Root Identifier
60 00 00 07 eb d5 a2 00
-
CIST Ext. Path Cost
00 00 00 00
-
CIST Bridge Identifier
60 00 00 07 eb d5 a2 00
-
CIST Port Identifier
80 01
-
Message age
00 00
-
Max age
14 00
-
Hello Time
02 00
-
Forward Delay
0f 00
-
Version 1 length
(should be 0)
00
-
Extra byte
00
If the Cisco BPDUs are parsed as
specified in the IEEE 802.1s
standard, some offsets and shifts
may cause wrong values for the
M-records and for the matching
fields that are located after the
version 3 length - CIST Internal
root path cost, CIST Bridge
identifier, CIST remaining hops.
Version 3 length
(Mrecords total length)
00 5a
-
MSTI configuration
Identifier (Key,
Revision, Name) 50
Bytes
.
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 64 b1 f4 bb 1f 3c
6d 4d a3 00 94 c1 11 b7 c0 92
The first byte of the
configuration is called selector,
and is omitted (or over-ridden by
the version 3 length field).
CIST Regional Root
Identifier
60 00 00 07 eb d5 a2 00
Fields’ order is flipped.
CIST Remaining hops
– 2 bytes instead of 1.
14 00
Extra byte - Cisco BPDU with no
MSTIs ends here and contains
the extra byte.
MSTI1
The whole M-Record structure is
different. In the 802.1s there is
no MSTID field. The priority of
the sending bridge and the port
priority are sent without bridge
ID and port ID of the sending
bridge.