Dhcp Server Options; Dhcp Options - Avaya Communication Server 1000 Installation And Commissioning Manual

DHCP server options

The DHCP server options known to work in almost every situation are 3, 7, 42, 66, 128, 151,
and 152:
• DHCP Option 3—the Default Gateway
• DHCP Option 7—the Syslog Server
• DHCP Option 42—the Time Server
• DHCP Option 60—the Class Identifier
• DHCP Option 66—the IP address of the TFTP Server
• DHCP Option 151—the IP address of the WLAN IP Telephony Manager 2245
• DHCP Option 152—the IP address for the optional WLAN Application Gateway 2246
DHCP options have the same format as the BOOTP vendor extensions. Options can be fixed
length or variable length. All options begin with a tag byte, which uniquely identifies the option.
Fixed length options without data consist of only a tag byte. The value of the length byte does
not include the tag and length fields.
Options containing NVT ASCII data (ideally) do not include a trailing NULL; however, the
receiver of such options must be prepared to delete trailing NULLs if they exist. The receiver
must not require that a trailing NULL be included in the data. With some variable-length options,
the length field is a constant but it still must be specified.

DHCP options

This section provides the IEEE definitions of the DHCP options. The term SHOULD, as used
in this section, is to be interpreted as described in [RFC2119].
DHCP option 1: Subnet Mask. Length: 6 bytes This option specifies the client's subnet mask.
If both the Subnet Mask and the router option are specified in a DHCP reply, this option
MUST be first.
00 01 02 03 04 05 06 07
Code
Code. 8 bits. Always set to 1.
Length. 8 bits. Always set to 4.
Mask. 32 bits. Subnet mask of the client.
RFCs: [RFC 2132] DHCP Options.
Updated by: RFC 3942.
Avaya WLAN IP Telephony Installation and Commissioning
08 09 10 11 12 13 14 15
Length
DHCP server options
16 17 18 19 20 21 22 23 24
25 26 27 28 29 30 31
Mask
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