DHCP Options Reference
Common DHCP options with code, name and description.
| Code | Name | Description |
|---|---|---|
| 0 | Pad | Padding |
| 1 | Subnet Mask | Client's subnet mask |
| 3 | Router | Default gateways |
| 6 | DNS Server | DNS resolvers |
| 12 | Host Name | Client hostname |
| 15 | Domain Name | Domain for resolving |
| 28 | Broadcast Address | Broadcast IP |
| 42 | NTP Servers | Time servers |
| 43 | Vendor-specific Information | |
| 50 | Requested IP Address | Client-requested address |
| 51 | IP Address Lease Time | Seconds |
| 53 | DHCP Message Type | 1=Discover 2=Offer 3=Request 4=Decline 5=Ack 6=Nak 7=Release 8=Inform |
| 54 | Server Identifier | DHCP server IP |
| 55 | Parameter Request List | Codes the client wants |
| 57 | Maximum DHCP Message Size | |
| 58 | Renewal Time (T1) | |
| 59 | Rebinding Time (T2) | |
| 60 | Vendor Class Identifier | |
| 61 | Client Identifier | |
| 66 | TFTP Server Name | |
| 67 | Boot File Name | |
| 82 | Relay Agent Information | |
| 119 | Domain Search | |
| 121 | Classless Static Route | |
| 125 | Vendor-Identified Vendor-Specific Information | |
| 255 | End | End marker |