APC AP89XX Manuel D’Utilisation

For problems that persist or are not described here, see the back cover of this manual.

Unable to ping the Rack PDU

If the Rack PDU’s Status LED is green, try to ping another node on the same 
network segment as the Rack PDU. If that fails, it is not a problem with the Rack 
PDU. If the Status LED is not green, or if the ping test succeeds, perform the 
following checks:
• Verify all network connections.
• Verify the IP addresses of the Rack PDU and the NMS.
• If the NMS is on a different physical network (or subnetwork) from the Rack 

PDU, verify the IP address of the default gateway (or router).

• Verify the number of subnet bits for the Rack PDU’s subnet mask.

Cannot allocate the 
communications port through a 
terminal program

Before you can use a terminal program to configure the Rack PDU, you must shut 
down any application, service, or program using the communications port.

Cannot access the command line 
interface through a serial 
connection

Make sure that you did not change the baud rate. Try 2400, 9600, 19200, or 38400.

Cannot access the command line 
interface remotely

• Make sure you are using the correct access method, Telnet or Secure SHell (SSH). 

An Administrator can enable these access methods. By default, Telnet is enabled. 

Enabling SSH automatically disables Telnet.

• For SSH, the Rack PDU may be creating a host key. The Rack PDU can take up to 

one minute to create the host key, and SSH is inaccessible for that time.

Cannot access the Web interface

• Verify that HTTP or HTTPS access is enabled.
• Make sure you are specifying the correct URL — one that is consistent with the 

security system used by the Rack PDU. SSL requires https, not http, at the 
beginning of the URL.

• Verify that you can ping the Rack PDU.
• Verify that you are using a Web browser supported for the Rack PDU. See 

• If the Rack PDU has just restarted and SSL security is being set up, the Rack PDU 

may be generating a server certificate. The Rack PDU can take up to one minute to 
create this certificate, and the SSL server is not available during that time.

Cannot communicate using 
Network Port Sharing

• If you are having communications problems with Network Port Sharing, check 

that the total length of network cable between up to four units is not more than 10 
meters. 

• If you are having communications problems with Network Port Sharing, check 

that a terminator is installed at both ends of up to four units that can be grouped 
together. 

• If you are using Network Port Sharing and do not see one or more of the units in 

the group, check that all units in the group are using the same firmware revision. 

You can download appropriate firmware revisions from the APC website.