By default, when 
or File | Open configuration is selected, Manager's Select IP Office menu appears. It performs a UDP broadcast to the address 255.255.255.255. This broadcast will only locate IP Office systems that are on the same network subnet as the PC running IP Office Manager.
The process above is called discovery. A UDP broadcast will not be routed to other networks and subnets. Therefore to find IP Office systems not located on the same subnet as the Manager PC, the following other options are supported.
•Specific Addressing
The Unit/Broadcast Address shown on the Select IP Office menu can be changed to the specific IP address of the required system. A single address is routable and so can be used to discover an IP Office system on another subnet.
•TCP Discovery Address Ranges
IP Office 3.2+ systems support discovery by TCP as well as UDP. To support this, a set of TCP addresses and address ranges can be specified for use by the Select IP Office discovery process.
•Known Units Discovery
The IP Office 4.0 Q2 2007 maintenance release adds supports for a system whereby IP Office Manager can write the details of systems it discovers to a file. The list of systems in that file can then be used for access to those systems. See Known Units Discovery.
•DNS Lookup
IP Office Manager 6.2 can be configured to locate IP Office systems using DNS name lookup. This requires the IP Office systems on a customer network to be added as names on the customer's DNS server and the Manager PC to be configured to use that server for DNS name resolution. The use of DNS is configured through File | Preferences | Discovery.
Changing the Initial Discovery Settings
The Discovery tab of the Manager Preferences menu can be used to set the UDP and TCP addresses used by the discovery process run by the Select IP Office menu.
1.Select File | Preferences menu.
2.Select the Discovery tab.
3.Under UDP Discovery you can enter the default UDP broadcast address to be used by the discovery process.
4.In the IP Search Criteria box you can enter IP addresses and IP address ranges for TCP discovery. Addresses should be separated by semi-colons, ranges by - dashes.