Modifying the Transparent Bridge Configuration

Use the Bridge Interface Add/Modify window to modify the configuration information for a port.

Enabling and Disabling the Spanning Tree Protocol

You can enable and disable the Spanning Tree Protocol (STP) on a specific port, if the port currently exists. STP is automatically enabled (the default) on all bridge ports at installation.

Caution: DIGITAL recommends that you keep STP enabled on all ports. Disabling STP may result in loops and severe network congestion.

Procedure:

Step Action
1 From the Bridge Interface Configuration window, locate the port for which you want to enable or disable STP.
2 Click Mod.
3 From the Bridge Interface  Add/Modify window,  locate Spanning Tree Protocol (STP) and choose Enable or Disable from the drop-down box.
4 Click Apply.

For background information on the STP, see About the Spanning Tree Protocol.

Forwarding Frames Using Manually Created Address Filters

By enabling manual mode, you can configure the switch to forward frames using only manually created address filters. Doing so allows you to strictly control traffic through selected ports and can provide an additional level of security to the desired subnetworks. For example, you may want to operate a port securely so that only one system is allowed to source and sink traffic on that port. To do so, you enable manual mode on the port.

You then create an address filter entry (permanent or static) for that system's MAC address, specifying only that port in the filter's allowed port map. In addition, if you want multicast or broadcast frames to be forwarded to that port, you must create an address filter for each such address, specifiying at least that port in the allowed port map. You configure the use of only manually created filters by enabling manual mode on selected ports.

When manual mode is enabled, the port's forwarding table that contains learned addresses is purged, and new addresses are not learned. However, you can still configure new MAC address filters manually. See Configuring Permanent Address Filters  for information about configuring filters manually. The addresses and locations of other network devices are relearned if manual mode is later disabled.

Field Descriptions

Port # Port's assigned number.
Associated Interface Interface that is paired with this port.
Port Sets the port's operational state (enabled or disabled).
Spanning Tree Protocol Sets the state of the spanning tree protocol (STP) (enabled or disabled).

Manual Mode (nonlistening)

Sets the state of bridge learning (enabled or disabled).  If manual mode is enabled, the port's forwarding table that contains learned addressess is purged, and new addresses are not learned. However, you can still configure MAC address filters manually.  See Configuring Permanent Address Filters  for more information.
Cost Sets the path cost.  Path cost can range from 1 to 65535, with higher values indicating higher costs.
Priority Sets the priority of a bridge, indicating the likelihood that it will be selected as the root bridge.