3Com 8807 Configuration Manual page 93

Setting
Broadcast/Multicast
Suppression on Ethernet
Port
c
Setting the Ethernet
Port Mode
effective Jumbo frame value for the 1536-1552 section is 1552, that for the
1553-9022 section is 9022, that for the 9023-9192 section is 9192, and that for
the 9193-10240 section is 10240.
To prevent port congestion resulting from broadcast/multicast packet flooding, the
switch supports broadcast/multicast suppression. You can enable
broadcast/multicast suppression by setting the speed percentage or bandwidth
values..
Perform the following configuration in Ethernet port view.
Table 76 Setting broadcast/multicast suppression on Ethernet port
Operation
Configure broadcast suppression ration
Ethernet port
Restore the default setting of broadcast
suppression on Ethernet port
Configure multicast suppression ration
Ethernet port
Restore the default setting of multicast
suppression on Ethernet port
CAUTION:
You cannot enable both broadcast suppression and multicast suppression
■
simultaneously on the same card. Namely, once you have enabled broadcast
suppression on some ports of a card, you cannot enable multicast suppression
on the other ports of the card, and vice versa.
If multicast suppression is enabled, broadcast packets are also suppressed at
■
the same time, while broadcast suppression does not work on multicast
suppression.
No distinction is made between known multicast and unknown multicast for
■
multicast suppression.
By default, the broadcast suppression ratio is 50%, while the multicast
suppression ratio is 100%.
Most ports adopt the LAN mode for general data exchange. The port must work in
WAN mode, however, if it needs special frame format for data transfer (such as in
fiber transmission). You can configure network mode available on the port using
the port-mode command.
Perform the following configuration in Ethernet port view.
Table 77 Setting the Ethernet port mode
Operation
Set the Ethernet port mode
Restore the default Ethernet port mode
Setting the Interval of Performing Statistics on Ports
Command
broadcast-suppression { ratio | bandwidth
bandwidth }
undo broadcast-suppression
multicast-suppression { ratio | bandwidth
bandwidth }
undo multicast-suppression
Command
port-mode { wan | lan }
undo port-mode
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