Network Configurations
55
DHCP Option for IPv4
The phone can obtain IPv4-related parameters in an IPv4 network via the DHCP option.
Note
: For more information on DHCP options, refer to
or
Topics
Supported DHCP Option for IPv4
DHCP Option 66, Option 43 and Custom Option
DHCP Option 42 Option 2
DHCP Option 12
DHCP Option 60
Supported DHCP Option for IPv4
The following table lists common DHCP options for IPv4 supported by Yealink phones.
Parameters
DHCP
Option
Description
Subnet Mask
1
Specify the client’s subnet mask.
Time Offset
2
Specify the offset of the client's subnet in seconds from Coordinated Universal
Time (UTC).
Router
3
Specify a list of IP addresses for routers on the client’s subnet.
Time Server
4
Specify a list of time servers available to the client.
Domain Name Server
6
Specify a list of domain name servers available to the client.
Host Name
12
Specify the name of the client.
Domain Server
15
Specify the domain name that the client should use when resolving host-
names via DNS.
Network Time Protocol
Servers
42
Specify a list of NTP servers available to the client by IP address.
Vendor-Specific Inform-
ation
43
Identify the vendor-specific information.
Vendor Class Identifier
60
Identify the vendor type.
TFTP Server Name
66
Identify a TFTP server when the 'sname' field in the DHCP header has been
used for DHCP options.
DHCP Option 66, Option 43 and Custom Option
During the startup, the phone automatically detects the DHCP option for obtaining the provisioning server address.
The priority is as follows: custom option > option 66 (identify the TFTP server) > option 43.
The phone can obtain the Auto Configuration Server (ACS) address by detecting option 43 during startup.
Note
: If you fail to configure the DHCP options for discovering the provisioning server on the DHCP server, enable the phone
to automatically discover the provisioning server address. One possibility is that connecting to the secondary DHCP server
that responds to DHCP INFORM queries with a requested provisioning server address. For more information, refer to
.
Related Topic
DHCP Option 42 Option 2
Yealink phones support using the NTP server address offered by DHCP.