13
present for the fiber port. When one fiber link is present and up, the fiber port can forward packets
over the link unidirectionally.
Figure 2 Forcibly bring up a fiber port
Configuration restrictions and guidelines
When you forcibly bring up a fiber port, follow these restrictions and guidelines:
•
The
loopback
,
shutdown
, and
port
up-mode
commands are mutually exclusive.
•
The following operations on a fiber port will cause link updown events before the port finally
stays up:
{
Configure both the
port up-mode
command and the
speed
or
duplex
command.
{
Install or remove fiber links or transceiver modules after you forcibly bring up the fiber port.
Configuration procedure
To forcibly bring up a fiber port:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter Ethernet interface
view.
interface
interface-type
interface-number
N/A
3.
Forcibly bring up the fiber
port.
port up-mode
By default, a fiber port is not forcibly
brought up, and the physical state of a
fiber port depends on the physical state
of the fibers.
Correct fiber
connection
When Ethernet interfaces
cannot be or are not forcibly
brought up
When Ethernet interfaces
are forcibly brought up
Fiber port Tx end Rx end
The fiber is disconnected.
Fiber link
Device A
Device B
Device A
Device B
Device A
Device B
The interface is down.
Packets