3Com 3CB9LF36T Plumbing Product User Manual


 
Broadcast, Multicast, and Flood Rate Limiting
25
Example:
If in a 1-second period, 3,500 fps are received from the
backplane port, 3,000 packets are transmitted out ports 3 and 10.
Port 11, however, which does not participate in module multicast rate
limiting, transmits the entire 3,500 fps.
Port Multicast
Packet-ingress Rate
Limiting
You can define an ingress rate limit for multicast packets per port on the
36-port 10/100BASE-TX Desktop Switching Module. Ingress rate limiting
is on a per-port basis only.
To set packet-ingress multicast thresholds for participating front-panel
ports, i
n the
bridge port multicastLimit
menu:
1
Select the ports that you want to participate in multicast rate limiting and
set their individual packet-ingress thresholds.
2
Specify whether you want to activate or deactivate multicast rate limits
and packet-ingress thresholds on these ports:
BcastOnly
— Deactivates multicast rate limits and the
packet-ingress threshold on the selected ports.
This setting removes the selected ports from participating in the
module’s multicast rate limiting.
McastBcast
— Activates multicast rate limits and the packet-ingress
threshold on the selected ports.
This setting allows the selected ports to participate in the module’s
multicast rate limiting.
These settings do not affect module broadcast or flood-rate limiting.
3
Enter the packet-ingress threshold that you want to use and the ports
that you want to limit using this threshold.
The range of permitted values is 0 to 200,000 fps. The default value is
4,000 fps. If incoming traffic exceeds the specified threshold on a
participating port for 7 continuous seconds, the module permanently
disables the port. User intervention is necessary to reenable the port.
Example:
CB9000@slot 5.1 [36L-E/FEN-TX-L2] (bridge/port):
multicastLimit
Select bridge ports (1-36|all|?) [1]:
Enter new frame type (BcastOnly,McastBcast): McastBcast
Enter new value (frames/sec). Enter 0 to filter all
(0-200000): 1000