H3C Technologies H3C SecPath F1000-E - Manual (Page 10)

9
Setting the MTU for an Ethernet Interface/Subinterface
The value of Maximum Transmission Unit (MTU) affects the fragmentation and re-assembly of IP packets.
Follow these steps to set the MTU for an Ethernet interface/subinterface:
To do… Use the command… Remarks
Enter system view system-view —
Enter Ethernet interface
view/Ethernet subinterface view
interface interface-type
{ interface-number |
interface-number.subnumber } —
Set the MTU mtu size
Optional
1500 bytes by default
NOTE:
Due to the QoS queue length limit (for example, the default length of an FIFO queue is 75), too small an
MTU will result in too many fragments, which will be discarded from the QoS queue. In this case, you can
increase MTU or QoS queue length properly. In Ethernet interface view, you can use the qos fifo
queue-length command to change the QoS queue length.
Configuring an Ethernet Interface to Operate in Promiscuous
Mode
Typically, an Ethernet interface receives only packets with matched destination MAC addresses. After
you configure an Ethernet interface to operate in promiscuous mode, however, the interface no longer
checks the MAC addresses in received packets. Rather, it receives all Ethernet packets with correct format.
Generally, you may need to configure a network listening port to operate in promiscuous mode.
Follow these steps to configure an Ethernet interface to operate in promiscuous mode:
To do… Use the command… Remarks
Enter system view system-view —
Enter Ethernet interface view
interface interface-type
interface-number
—
Configure the Ethernet interface to
operate in promiscuous mode
promiscuous
Required
By default, an Ethernet interface does
not operate in promiscuous mode.