14.
Multiple Spanning Tree Protocol (MSTP)
MN700004 Rev 01
159
(STP). The command forces renegotiation of the LAN’s protocol MSTP/STP with the
neighboring bridges.
Command Syntax
device-name
(config-if
UU/SS/PP
)#
mstp detect-protocols
Cisco Compliance
The Nokia implementation for Cisco compliance requires several changes in the BPDUs
format and the way the devices operate in Cisco Compliant mode.
An agreement flag within BPDUs is not sent from the designated port, when the device is in
Cisco compliant mode, even if the port is synced.
A port is considered synced, in Cisco compliant mode, if it has received a proposal on a point-
to-point link (Cisco does not send agreement flag within its BPDUs to the designated port).
When the device is not in Cisco compliant mode, a root port is synced only if it recieves an
agreement together with the proposal flag from the designated port. If the port is not synced, it
does not perform fast transition.
Example Comparison Between Nokia ESB26 and Cisco BPDU Formats:
The following is an example of parsing two BPDUs. Table 14-7 displays a Nokia ESB26
generated BPDU that matches IEEE 802.1s. The BPDU includes two M-records. Table 14-8
displays an example of a Cisco BPDU.
NOTE
In Cisco compliance mode, Nokia ESB26 generates and parses BPDUs with the format of
Cisco BPDUs as it is displayed in Table 14-8.
Before parsing the BPDUs, first are displayed the dumps - BiNOS dump and Cisco dump.
The differences from the 802.1s specification in Table 14-8 are displayed bolded.
BiNOS Dump
01 80 c2 00 00 00 00 a0 12 11 29 92 00 89 42 42
03 00 00 03 02 4e 80 00 00 a0 12 11 29 92 00 00
00 00 80 00 00 a0 12 11 29 92 80 0b 00 00 14 00
02 00 0f 00 00 00 60 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 01 60 b0 d3 6e cc e1
45 40 14 da 65 22 bd 08 f3 cd 00 00 00 00 80 00
00 a0 12 11 29 92 28 4e 80 01 00 a0 12 11 29 92
00 00 00 00 80 80 28 4e 80 02 00 a0 12 11 29 92
00 00 00 00 80 80 28
Cisco Dump
01 80 c2 00 00 00 00 08 a3 37 f1 c1 00 84 42 42
03 00 00 03 02 68 60 00 00 07 eb d5 a2 00 00 00
00 00 60 00 00 07 eb d5 a2 00 80 01 00 00 14 00
02 00 0f 00 00 00 00 5a 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 60 00 00 07 eb d5