H3C S5500-SI Series, Operation Manual

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1-7
To do… Use the command… Remarks
Set the interval for collecting
statistics on the Ethernet port
flow-interval interval
Optional
By default, the interval for
collecting port statistics is 300
seconds.
Enabling Forwarding of Jumbo Frames
Due to tremendous amount of traffic occurring on an Ethernet interface, it is likely that some frames
greater than the standard Ethernet frame size are received. Such frames (called jumbo frames) will be
dropped. With forwarding of jumbo frames enabled, the system does not drop all the jumbo frames.
Instead, it continues to process jumbo frames with a size greater than the standard Ethernet frame size
and yet within the specified parameter range.
In interface configuration mode (Ethernet interface view/port-group view), you can enable jumbo frames
that can pass through the Ethernet interface.
z
If you execute the command in Ethernet interface view, the configurations take effect only on the
current interface.
z
If you execute the command in port-group view, the configurations take effect on all ports in the port
group.
Follow these steps to enable the forwarding of jumbo frames:
To do… Use the command… Remarks
Enter system view system-view —
port-group manual
port-group-name
In port-group
view
jumboframe enable
interface interface-type
interface-number
Enable the
forwarding of
jumbo
frames
In Ethernet
interface view
jumboframe enable
Use any command.
By default, the device
allows jumbo frames with
the length of 9.216 bytes to
pass through all Layer 2
Ethernet interfaces.
Enabling Loopback Detection on an Ethernet Interface
If a port receives a packet that it sent out, a loop occurs. Loops may cause broadcast storms. The
purpose of loopback detection is to detect loops on an interface.
When loopback detection is enabled on an Ethernet interface, the device periodically checks whether
the ports have any external loopback. If it detects a loopback on a port, the device will set that port to be
under loopback detection mode.
z
If loops are detected on an access port, the port will be blocked. Meanwhile, trap messages will be
sent to the terminal, and the corresponding MAC address forwarding entries will be removed.
z
If loops are detected on a trunk port or a hybrid port, trap messages are sent to the terminal. If the
loopback detection control function is also enabled on the port, the port will be blocked, trap
messages will be sent to the terminal, and the corresponding MAC address forwarding entries will
be removed.
Follow these steps to configure loopback detection: