Use the
mdix auto
command in the interface configuration mode to enable an automatic media-dependent
interface with crossover detection. After you enable the automatic media-dependent interface, the device
detects the required cable type for copper Ethernet connections and configures the interface accordingly. Then,
use either a crossover or a straight-through cable for connecting to a copper 10/100/1000 port. If the
mdix
auto
command fails to enable the interface, connect the cable through SFP modules.
Connect SFP Modules
Before you begin this task, ensure that you have read and understood the safety warnings in the
Precautions for Module Installation and Removal
section of the
handout topic.
Use only Cisco SFP modules on a Cisco device. Each SFP module has an internal serial EEPROM that is
encoded with security information. This encoding provides a way for Cisco to identify and validate that the
SFP modules meet the requirements of the device.
We recommend that you wait for 30 seconds between the removal and insertion of an SFP module from the
device. The wait period allows the transceiver software to initialize and synchronize with the device. Changing
an SFP before this wait period could result in transceiver initialization issues that disable the SFP.
Caution
This section provides procedures for installing and connecting SFP modules. Also, it provides the procedure
for removing SFP modules.
Install SFP Modules
We strongly recommend that you do not install (or remove) an SFP module with its cables connected because
of the potential damage that may be caused to the cables, the cable connector, or the optical interfaces in the
SFP modules. Disconnect all cables before removing or installing an SFP module.
Removing and installing an SFP module can shorten its useful life. Do not remove and insert SFP modules
unless necessary.
Caution
The following figure shows an SFP module that has a bale-clasp latch.
Figure 25: SFP Module with Bale-Clasp Latch
Some SFP modules identify the top side of the module with send (TX) and receive (RX) has markings or
arrows that show the direction of the connection. If the SFP module that you are using has such markings,
use them to identify the top of the module.
Cisco ASR-920-20SZ-M Aggregation Services Router Hardware Installation Guide
42
Install the Router
Connect SFP Modules
