Category Archives: Datacenter

APC PDU configuration trick

I was trying to configure an APC7811 PDU, which has a network port for remote access. It’s a metered PDU so you can log in remotely and look at power consumption.

I’d never had to configure one before so I just popped in the CD that came with it and tried to configure an IP address by using the discovery tool. Regardless of which IP address I tried, I kept getting “The IP is already in use on the network.”

This configuration method is in the documentation, but it’s buried at the end… I think I’ll use this every time now as it’s fast and doesn’t require the vendor’s CD.

The MAC address is on the back of the PDU and on the Quality Assurance slip included in the package.

  1. Use ARP to define an IP address for the PDU,
    and use the PDU’s MAC address in the ARP
    command. For example, to define an IP
    address of for the PDU that has
    a MAC address of 00 c0 b7 63 9f 67, use one
    of the following commands:

    Windows command format:
    arp -s 00-c0-b7-63-9f-67

    LINUX command format:
    arp -s 00:c0:b7:63:9f:67

  2. Use Ping with a size of 113 bytes to assign the
    IP address defined by the ARP command. For

    Windows command format:
    ping -l 113

    LINUX command format:
    ping -s 113

  3. Use Telnet to access the PDU at its newly
    assigned IP address. For example:


  4. Use apc for both user name and password.

At this point the IP address is configured for the interface, you can browse to the IP via HTTP. Don’t forget to delete your static ARP entry.