H3C S7500X Series Interface Configuration Manual page 24

Figure 2 Forcibly bring up a fiber port
Correct fiber
connection
Device A
Device B
Fiber port
Configuration restrictions and guidelines
When you forcibly bring up a fiber port, follow these restrictions and guidelines:
•
This feature is not supported on interfaces on the following interface modules:
Interfaces numbered 25 through 28 on the LSQM2GP24TSSC0 and LSQM2GT24TSSC0

modules.
Interfaces numbered 9 and 10 on the LSQM1PT8TSSC0 modules.

Interfaces numbered 25 and 26 on the LSQM1PT24TSSC0 modules.

Interfaces numbered 25 through 28 on the LSQM2GP24TSSA0 modules.

Interfaces numbered 45 through 48 on the LSQM2GP44TSSC0 and LSQM2GT24PTSSC0

modules.
•
For fiber ports connected to the same physical link to operate correctly, you must configure this
feature for both of them.
•
The port up-mode, shutdown, and loopback commands are mutually exclusive.
•
A fiber Ethernet port does not support this feature if the port is shut down by a protocol or by
using the shutdown command.
•
A fiber Ethernet port does not support this feature if the port joins an aggregate group.
•
Either of the following operations on an interface forcibly brought up will cause the interface to
go down before staying physically up:
Configure the speed, duplex, or port fec mode command on the interface.

Remove and install fibers or transceiver modules.

•
A GE fiber port forcibly brought up cannot correctly forward traffic if it is installed with a
fiber-to-copper converter, 100/1000-Mbps transceiver module, or 100-Mbps transceiver module.
To solve the problem, use the undo port up-mode command on the fiber port.
When Ethernet interfaces
cannot be or are not forcibly
brought up
Tx end Rx end
Device A
Device B
Fiber link
Packets
15
When Ethernet interfaces
are forcibly brought up
Device A
Device B
The fiber is disconnected.
The interface is down.