Allied Telesis AT-S62 - Manual (Page 99)

AT-S62 Menus Interface User’s Guide
Section I: Basic Operations 99
2 - Broadcast Filter
Most frames on an Ethernet network are usually unicast frames. A
unicast frame is a frame that is sent to a single destination. A node
sending a unicast frame intends the frame for a particular node on
the network.
Broadcast frames are different. Broadcast frames are directed to
all nodes on the network or all nodes within a particular virtual
LAN. Broadcast packets can perform a variety of functions. For
example, some network operating systems use broadcast frames
to announce the presence of devices on a network.
The problem with broadcast frames is that too many of them
traversing a network can impact network performance. The more
bandwidth consumed by broadcast frames, the less available for
unicast frames.
Should the performance of your network be impacted by heavy
broadcast traffic, you can use this parameter to limit the number
of broadcast frames forwarded by the switch ports and so limit the
number of broadcast frames on your network.
Activating this feature on a port discards all egress broadcast
packets on the port.
It should be noted that the filtering takes place only on egress
broadcast packets—packets that a port is transmitting. This filter
does not apply to ingress broadcast packets.
Possible settings for this parameter are:
Enabled The port discards all egress broadcast frames.
Disabled The port transmits egress broadcast frames. This is
the default setting.
3 - MDI/MDIX Crossover
You use this selection to set the wiring configuration of a twisted
pair port. This option only appears when option 4 - Negotiation,
which is used to activate and deactivate Auto-Negotiation, is set
to Manual.
When selection 4 - Negotiation is set to Auto, which activates
Auto-Negotiation on a port, this option is hidden in the menu and
a twisted pair port uses auto-MDI/MDI-X to automatically set its
wiring configuration. This feature enables a port to configure itself
automatically as MDI or MDI-X when connected to an end node.
This allows you to use a straight-through twisted pair cable when
connecting any type of network device to a port on the switch.
The auto-MDI/MDI-X feature is only available when a port is using
Auto-Negotiation to set its speed and duplex mode. It is also the
only setting available when a port’s speed and duplex are set
through Auto-Negotiation.