nni-mstp boot config flag

Table 1. nni-mstp boot flag product support
Feature	Product	Release introduced
nni-mstp boot flag (boot config flags nni-mstp)	5320 Series	Fabric Engine 8.6
	5420 Series	VOSS 8.4
	5520 Series	VOSS 8.2.5
	5720 Series	Fabric Engine 8.7

The nni-mstp boot flag changes the default behavior of the MSTP on SPBM network-to-network interface (NNI) ports. The Common and Internal Spanning Tree (CIST) is disabled automatically on the NNI, and the NNI ports can only be members of backbone VLANs (B-VLAN).

During startup, if you have non-B-VLAN on SPBM NNI ports in your configuration file, the system sets the nni-mstp flag to true (if it was not already set to true) and enables MTSP on SPBM NNI ports, and all other configurations remain the same. Save your configuration file. If you do not save your configuration, you continue to see the following message on reboot:
```
Warning
Detected brouter and/or vlans other than BVLANs on NNI ports. Setting the boot config
flag nni-mstp to true. Saving configuration avoids repetition of this warning on reboot.
```
Note

When the nni-mstp flag is set to true, only MSTI 62 is disabled on the SPBM NNI ports. You can add the SPBM NNI ports to any VLAN.
If you configure the nni-mstp boot configuration flag to false (default), the system checks to make sure that the SPBM NNI ports do not have brouter (IPv4 or IPv6) or non-SPBM VLANs configured. The nni-mstp flag is then set to false. Save your configuration file, and reboot the switch for the configuration change to take effect.

Note

Ensure that all SPBM NNI ports in non-B-VLAN are removed prior to setting the nni-mstp flag to false.

Example: Configuring nni-mstp to true

Switch:1>enable
Switch:1#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch:1(config)#boot config flags nni-mstp
Warning: Please save the configuration and reboot the switch for this configuration to take effect.
Switch:1(config)#