Cisco 7920 Administration Guide - Page 188

Resolving Startup and Connectivity Problems Chapter 9 Troubleshooting the Cisco Wireless IP Phone 7920 If you are using DHCP, check the IP addresses distributed by your DHCP server. Be aware of DHCP conflicts and duplicate IP addresses. Refer to Understanding and Troubleshooting DHCP in Catalyst Switch or Enterprise Networks, available at this URL: http://www.cisco.com/en/US/tech/tk648/tk361/technologies_tech_note09186a00 800f0804.shtml For information about determining and changing IP addressing, see Chapter 5, "Configuring Network Profiles on the Cisco Wireless IP Phone 7920." Verifying DNS Settings If you are using DNS to refer to Cisco CallManager, you must ensure that you have specified a DNS server. You should also verify that there is a CNAME entry in the DNS server for the Cisco CallManager system. You must also ensure that DNS is configured to do reverse look-ups. The default setting on Windows 2000 is to perform forward-only look-ups. For information about determining and changing DNS settings, see "Modifying DHCP Settings" section on page 5-4 Verifying Cisco CallManager Settings The Cisco Wireless IP Phone 7920 attempts to open a TCP connection to all the Cisco CallManager servers that are part of the assigned Cisco CallManager group. Take one of these actions to verify Cisco CallManager settings: • On the Cisco Wireless IP Phone 7920, choose Menu > Network Config > Current Configuration and look at the CallManager 1-4 options. (See"Viewing the Current Configuration" section on page 8-17. ) • If none of the Cisco CallManager options contain IP addresses or show Active or Standby, the phone is not properly registered with Cisco CallManager. See the "Registering the Phone with Cisco CallManager" section on page 9-5 for tips on resolving this problem. Cisco Wireless IP Phone 7920 Administration Guide for Cisco CallManager Release 4.0 and 4.1 9-8 OL-7104-01