Yealink SIP-T23P [78/841] Dhcp option

Administrator’s Guide for SIP-T2 Series/T19(P) E2/T4 Series IP Phones

4. Enter the desired values in the Primary DNS and Secondary DNS fields.

5. Click Confirm to accept the change.

A dialog box pops up to prompt that settings will take effect after a reboot.

6. Click OK to reboot the phone.

To configure static DNS when DHCP is used via phone user interface:

1. Press Menu->Settings->Advanced Settings (default password: admin)

->Network->WAN Port->IPv4->DHCP IPv4 Client.

2. Press or , or the Switch soft key to select Enabled from the Static DNS field.

3. Enter the desired values in the IPv4 Pri.DNS and IPv4 Sec.DNS fields respectively.

4. Press the Save soft key to accept the change.

The IP phone reboots automatically to make settings effective after a period of time.

DHCP provides a framework for passing information to TCP/IP network devices. Network

and other control information are carried in tagged data items that are stored in the

options field of the DHCP message. The data items themselves are also called options.

DHCP can be initiated by simply connecting the IP phone with the network. IP phones

broadcast DISCOVER messages to request the network information carried in DHCP

options, and the DHCP server responds with specific values in corresponding options.

The following table lists common DHCP options supported by IP phones.

Parameter

DHCP Option

Description

Subnet Mask

Specify the client’s subnet mask.

Time Offset

Specify the offset of the client's subnet in

seconds from Coordinated Universal Time