Using the 7C0x SmartSwitch Bridge View
MtuExceedDiscard
Mtu stands for “maximum transfer unit”; it is the largest frame size that can be processed by the 7C0x SmartSwitch. A port discards any received frames that are larger than the Mtu; this field lists how many such frames were discarded.
The information in the Bridge Statistics window is a snapshot of the data. When you open the Bridge Statistics window, the application polls the devices for information. Devices are not polled again until you click mouse button 1 on the Update button, or close, then
NOTE |
When a device is reset, statistics windows and/or statistics displays in the Bridge View windows may display very large numbers for one polling interval. This is due to the resetting of counters.
The Filtering Database Window
In Transparent bridging, each bridge port uses the device’s Filtering Database to determine a packet’s route through the bridge. The Filtering Database is created from permanent entries made via management, and from entries learned as the bridge collects and stores the source address and port association from each packet it receives.
When in the Forwarding state, the bridge examines each received packet and compares the destination address to the contents of the Filtering Database. If the destination address is located on the network from which the packet was received, the bridge filters (does not forward) the packet. If the destination address is located on a different network, the bridge forwards the packet to the appropriate network. If the destination address isn’t found in the Filtering Database, the bridge forwards the packet to all networks. To keep Filtering Database entries current, older entries are purged after a period of time, which is called the Dynamic Ageing Time.
The Filtering Database has two types of entries: Forwarding and Static. The Forwarding view of the Filtering Database contain addresses that the bridge learns from network traffic (also known as dynamic entries) as well as all the static entries. Learned entries are subject to the bridge’s Dynamic Ageing Timer; entries that aren’t accessed within the time specified by the ageing timer are purged. Static entries may be subject to the ageing timer, depending on how the entries were added. Static entries enter the Filtering Database in two ways: either automatically, when permanent database entries are copied to the Filtering Database, or manually when you move a Forwarding entry to the Static Table.
The Filtering Database Window |
