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Fields on the screen are described below:
Field
Description
Time Range ID
Displays corresponding time range ID.
Absolute Time
Configure this time range's absolute time (from 2000, January 1st to
2035, December 31th.).
Periodic Time
Configure this time range's periodic time (from Mon. to Sun.).
Add
Click to add a new time slice.
ID
Displays time slice ID (1~4).
Beginning Time
Displays time slice's starting time (00:00~23:59).
Ending Time
Displays time slice's ending time (00:00~23:59).
Delete
Click to delete the corresponding time slice.
Back
Click to go back to the Time Range page.
4.6 Device Management
4.6.1 MAC
MAC Forwarding Table Overview
An Ethernet device uses a MAC address table for forwarding frames through unicast instead of broadcast. This
table describes from which port a MAC address (or host) can be reached. When forwarding a frame, the device first
looks up the MAC address of the frame in the MAC address table for a match. If the switch does not find an entry,
it broadcasts the frame. The MAC address table maintains a map of MAC addresses and corresponding forwarding
ports for fast frame forwarding. A MAC address table entry includes the following information: destination MAC
address, VLAN ID to which the port belongs and forwarding egress port number. MAC address length is 6 bytes.
The format is XXXX-XXXX-XXXX and ―X‖ is hexadecimal.
When forwarding a frame, the device adopts the following forwarding modes based on the MAC address table:
Unicast mode: If an entry is available for the destination MAC address, the device forwards the frame out of the
outgoing port indicated by the MAC address table entry.
Broadcast mode: If the device receives a frame with the destination address whose lowest bit of the second byte is 1,
or no entry is available for the destination MAC address, the device forwards the frame to all ports except the
receiving port, i.e. broadcast packets, multicast packets and unknown unicast packets will be forwarded.
MAC Forwarding Table Aging Scheme
To adapt to network changes and prevent inactive entries from occupying limited table space, an aging mechanism
is adopted for dynamic MAC address entries. Each time a dynamic MAC address entry is obtained or created, an
aging timer starts. If the entry has not updated when the aging timer expires, the device deletes the entry. If the
entry has updated before the aging timer expires, the aging timer restarts. This aging mechanism ensures that the
MAC address table can quickly update to accommodate the latest network changes. (Click
Administration >
System Info > MAC Age
to configure MAC age.) Note: The MAC aging mechanism takes effect on dynamic
MAC address entries only.
Types of MAC address table entries
A MAC address table can contain the following types of MAC entries:
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