My Ethernet device won't connect to the network

If the Ethernet device is a computer, it is possible that the computer does not have DHCP client enabled, which allows it to obtain an IP address automatically and join the network.

To enable DHCP on Windows:

1. In Windows 7: Open Network Connections by clicking the Start button, and then clicking Control Panel.  In Windows 8: Drag the mouse to the top right corner of the screen, click on the Settings icon, then click on Control Panel.  In the search box at the top of the Control Panel, type adapter, and then, under Network and Sharing Center, click View network connections.

2. Right-click the connection that you want to change, and then click Properties. If you're prompted for an administrator password or confirmation, type the password or provide confirmation.

3. Click the Networking tab. Under This connection uses the following items, click either Internet Protocol Version 4 (TCP/IPv4) or Internet Protocol Version 6 (TCP/IPv6), and then click Properties.

1.To specify IPv4 IP address settings, do one of the following:

  • To get IP settings automatically using DHCP, click Obtain an IP address automatically, and then click OK.
  • To specify an IP address, click Use the following IP address, and then, in the IP addressSubnet mask, and Default gateway boxes, type the IP address settings.

2. To specify IPv6 IP address settings, do one of the following:

  • To get IP settings automatically using DHCP, click Obtain an IPv6 address automatically, and then click OK.
  • To specify an IP address, click Use the following IPv6 address, and then, in the IPv6 addressSubnet prefix length, and Default gateway boxes, type the IP address settings.

3. To specify DNS server address settings, do one of the following:

  • To get a DNS server address automatically using DHCP, click Obtain DNS server address automatically, and then click OK.
  • To specify a DNS server address, click Use the following DNS server addresses, and then, in the Preferred DNS server and Alternate DNS server boxes, type the addresses of the primary and secondary DNS servers.

The Internet Protocol Version 4 (TCP/IPv4) Properties dialog box

To enable DHCP on Mac OS X:

  1. Click on the Apple and select "System Preferences"
  2. Choose "Network"
  3. In the "Show" drop-down list, make sure that "Built-in Ethernet" is selected
  4. In the "TCP/IP" tab, delete everything in the boxes, and select "Using DHCP" from the "Configure" drop-down list
  5. Click "Save" and close "System Preferences"
  6. Restart your machine to apply the above changes

If you still cannot connect:

  • Check DHCP Lease Time to be sure it is not expiring. The default is 3600 seconds (1 Hour). Try 86400.
  • Check number of CPEs in the DHCP Pool to be sure it is not being exhausted. 
  • Check the IP address assignments under the Basic > DHCP section.