3Com Switch 7750 Series
Command Reference Guide – Multicast Chapter 2 Common IP Multicast Configuration Commands
2-14
When the switch receives a multicast packet, the switch will search the multicast
forwarding entry according to the source address and destination address of the packet.
If the matching forwarding entry is found and the packet is received on the right ingress
of the forwarding entry, the packet will be forwarded according to the forwarding entry. If
the packet is not received on the right ingress of the forwarding entry, the packet is
regarded as a wrongif packet. The wrongif packet will be reported to the CPU.
In some network, many wrongif packets will be reported to the CPU of the switch, thus
aggravating the workload of the switch. In this case, you can configure the holdtime of
wrongif packets, so that the wrongif packets will be dropped instead of being forwarded
to the CPU of the switch, and the CPU will be prevented from being stricken by too
many packets.
In the configured holdtime, wrongif packets are not reported to the CPU, so that the
CPU can be prevented from being stricken by too many multicast packets.
Example
# Set the holdtime of wrongif packets to 60 seconds.
<3Com> system-view
System View: return to User View with Ctrl+Z.
[3Com] multicast wrongif-holdtime 60
2.1.12 multicast-source-deny
Syntax
multicast-source-deny enable [ interface interface-list ]
undo multicast-source-deny enable [ interface interface-list ]
View
System view, Ethernet port view
Parameter
interface-list: Specifies Ethernet port list, expressed in the form of interface-list =
{ { interface-type interface-num | interface-name } [ to { interface-type interface-num |
interface-name } ] }&<1-10>. The interface-number argument refers to one single
Ethernet port, expressed in the form of interface-number = { interface-type
interface-number | interface-name }, where the interface-type argument refers to the
port type, the interface-number argument refers to the port number, and the
interface-name argument refers to the port name. For meanings and value ranges of
interface-type, interface-number and interface-name, refer to the parameters in the
section “Port Basic Configuration” in this manual.