Determine Dns Or Connectivity Issues; Check Dhcp Settings - Cisco 7800 Series Administration Manual

Cisco IP Phone Troubleshooting

Determine DNS or Connectivity Issues

Procedure
Step 1 Use the Reset Settings menu to reset phone settings to their default values.
Step 2
Modify DHCP and IP settings:
a) Disable DHCP.
b) Assign static IP values to the phone. Use the same default router setting that other functioning phones
use.
c) Assign a TFTP server. Use the same TFTP server that other functioning phones use.
Step 3 On the Cisco Unified Communications Manager server, verify that the local host files have the correct Cisco
Unified Communications Manager server name mapped to the correct IP address.
Step 4 From Cisco Unified Communications Manager, choose System > Server and verify that reference to the
server is made by the IP address and not by the DNS name.
Step 5
From Cisco Unified Communications Manager, choose Device > Phone. Click Find to search for this phone.
Verify that you have assigned the correct MAC address to this Cisco IP Phone.
Step 6
Power cycle the phone.
Related Topics

Check DHCP Settings

Procedure
Step 1
On the phone, press Applications
Step 2 Select Admin Settings > Network Setup > IPv4 Setup.
Step 3
Check the DHCP server field.
If you have assigned a static IP address to the phone, you do not need to enter a value for the DHCP Server
option. However, if you are using a DHCP server, this option must have a value. If no value is found, check
your IP routing and VLAN configuration. See the Troubleshooting Switch Port and Interface Problems
document, available at this URL:
https://www.cisco.com/en/US/customer/products/hw/switches/ps708/prod_tech_notes_list.html
Step 4 Check the IP Address, Subnet Mask, and Default Router fields.
If you assign a static IP address to the phone, you must manually enter settings for these options.
Step 5
If you are using DHCP, check the IP addresses that your DHCP server distributes.
See the Understanding and Troubleshooting DHCP in Catalyst Switch or Enterprise Networks document,
available at this URL:
Basic Reset, on page 207
Determine the Phone MAC
Cisco IP Phone 7800 Series Administration Guide for Cisco Unified Communications Manager
Address, on page 60
.
Determine DNS or Connectivity Issues
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