34CHAPTER 4: CONFIGURING THE SWITCH
To determine the exact IP address that the Switch assigns to itself during auto IP configuration, check the sticker on the base of the Switch. This sticker contains the MAC address and default IP address of the Switch.
To detect its IP information using the automatic configuration process, the Switch goes through the following sequence of steps:
1The Switch tries to configure itself with the default IP address 169.254.x.y, where x and y are converted from the last two bytes of its MAC address.
For example, if the MAC address is
08004E000102, the IP address would be 169.254.1.2. This address is used if the Switch is operating in a standalone mode, or no other switches on the network have this IP address.
The Switch also assigns the subnet mask 255.255.0.0 (default class B mask) to itself.
2If this default IP address is already in use on the network, then the Switch detects this, and increments the last byte of the MAC address by one to generate its IP address.
The IP address would therefore become 169.254.1.3.
3The Switch repeats step 2 until an unused IP address is found.
3Com recommends using automatic IP configuration only for the initial setup. Once you gain access to the console, you should assign an IP address to the Switch (either by using DHCP or assigning a static IP address) to ensure successful communication between the Switch and other network devices.
IP Setup
To set the IP address for the Switch:
1Click Administration, then IP Setting on the menu. The IP Settings screen appears. Follow the IP Setup Wizard to complete the setup.
This wizard can also be used to set system name, location and contact information.
