(Optional) Configuring Option Information Requested by a DHCP Client
Context
The Option 55 field in DHCP Request messages is used to set the request option list. DHCP clients use this option to specify network configuration parameters that need to be obtained from the DHCP server. You can run the dhcp client request option-list exclude command to set a list of default options that are excluded from the Option 55 field or run the dhcp client request option-list command to set a list of other options that the Option 55 field carries besides the default options based on network requirements. The other options include option 4, 7, 17, 42, 43, 66, 67, 120, and 129.
For option meanings, see DHCP Messages in Configuration- IP Service Configuration Guide - DHCP Configuration.
Procedure
- Enter the system view.
system-view - Enter the interface view or sub-interface view.
interface interface-type interface-number [.subinterface-number ]
Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731S-H, S5731-S, S5731S-S, S6720-HI, S5732-H, S6730-H, S6730S-H, S6730-S, S6730S-S, S6720-EI, and S6720S-EI support sub-interfaces.
- (Optional) On an Ethernet interface, run undo portswitch
The interface is switched to Layer 3 mode.
By default, an Ethernet interface works in Layer 2 mode.
Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support switching between Layer 2 and Layer 3 modes.
- Configure a list of default request options that are excluded from the Option 55 field in DHCP Request messages.
dhcp client request option-list exclude option-code &<1-8>By default, the device does not configure the option to be excluded from the DHCP client request list.
- Configure a list of request options that the Option 55 field in DHCP Request messages carries besides the default options.
dhcp client request option-list option-code &<1-9>By default, the Option 55 field in DHCP Request packets carries only default request options.