Solving Communication Problems 57SolvingCommunicationProblemsIf you experience communication problems with the Switch, ensure that:■ The Switch IP address and Management VLAN ID has beenconfigured.■ If the Switch is separated from your management application by arouter, ensure that the default gateway IP address within the Switch isthe same as the IP address of the router.■ The Switch’s IP address has been entered correctly in your networkmanagement application (such as 3Com Network Director).The following is a brief overview of IP addressing, and how to obtain aregistered IP address.IP AddressingTo be managed correctly, each device on your network (for example aSwitch or Hub) must have a unique IP address. IP addresses have theformat n.n.n.n where n is a decimal number between 0 and 255. Anexample IP address is 192.168.100.8.The IP address is split into two parts:■ The first part (‘192.168.100’ in the example) identifies the network onwhich the device resides■ The second part (‘.8’ in the example) identifies the device within thenetworkThe natural subnet mask for this example is 255.255.255.0.If your network has a connection to the external IP network, that is, youaccess the Internet, you must apply for a registered IP address.How do you obtain a registered IP Address?The IP registration system ensures that every IP address used is unique; ifyou do not have a registered IP address, you may be using an identicaladdress to someone else and your network will not operate correctly.InterNIC Registration Services is the organization responsible forsupplying registered IP addresses. The following contact information iscorrect at time of publication:World Wide Web site: http://www.internic.net10014914AA.book Page 57 Friday, July 7, 2006 2:08 PM