Installation guide

4-148 Motorola RF Switch System Reference Guide
4.9.5.2 Editing an Existing AP Firmware Image
To modify the AP Firmware Image settings:
1. Select Network Setup > Access Port from the main menu tree.
2. Click the AP Firmware tab.
3. Select an AP Image Type from the AP Image Upload table.
4. Click the Edit button to display a screen to change the AP Image Type or AP Image File.
5. Modify the AP Image Type as necessary.
6. Modify the AP Image File as necessary. You can browse the switch file systems using the browser icon.
AP images must be on the flash, system, nvram or usb file systems in order for them to be selected.
7. Click the OK button to save the changes and return to the AP Firmware tab.
4.10 Multiple Spanning Tree
Multiple Spanning Tree Protocol (MSTP) provides a VLAN-aware protocol and algorithm to create and
maintain a loop-free network. It allows the configuration of multiple spanning tree instances. This ensures
a loop-free topology for 1 or more VLANs. It allows the network administrator to provide a different path for
each group of VLANs to better utilize redundancy.
MSTP allows rapid convergence similar to Rapid Spanning Tree Protocol (RSTP). RSPT is an independent
protocol and MSTP does not use RSTP. Since MSTP allows VLANs to be grouped in an instance, each
instance can have its own spanning-tree topology independent of other spanning-tree instances. This
architecture provides multiple forwarding links for data traffic, load balancing and therefore, reduces the
number of spanning-tree instances required to support a large number of VLANs.
Using MSTP, the network can be divided into regions. All switches within a region use the same VLAN to
instance mapping. The entire network runs a spanning tree instance called the Common Spanning Tree
instance (CST) that interconnects regions as well as legacy (STP and RSTP) bridges. The regions run on a local
instance for each configured MSTP instance.
The network-wide spanning tree for instance 0 is known as the Common Spanning Tree (CST). A spanning
tree for any other instance, which is local to a region, is known as an Internal Spanning Tree (IST). The
Common and Internal Spanning Tree (CIST) (which consists of the CST as well as all ISTs across regions)
interconnects all bridges in the network.
The following definitions describe the STP instances that define an MSTP configuration:
• Common Spanning Tree (CST) – MSTP runs a single spanning tree instance (called the Common Spanning
Tree) that interconnects all the bridges in a network. This instance treats each region as a single bridge.
In all other ways, it operates exactly like Rapid Spanning Tree (RSTP).
• Common and Internal Spanning Trees (CIST) – CIST contains all of the ISTs and bridges not formally
configured into a region. This instance interoperates with bridges running legacy STP and RSTP
implementations.
• Multiple Spanning Tree Instance (MSTI) – The MSTI is identified by an MSTP identifier (MSTPid) value
from 1 to 15. This defines an individual instance of a spanning tree. One or more VLANs can be assigned
to an MSTI. A VLAN cannot be assigned to multiple MSTIs. The multiple spanning tree instance 0 is
always present. VLANs not explicitly assigned to an instance are assigned to instance 0.
• MSTP Region – These are clusters of bridges that run multiple instances of the MSTP protocol. Multiple
bridges detect they are in the same region by exchanging their configuration digest (which is dependent