| BOOTP/DHCP option 1, Subnet Mask |
Description:
| Length: | 6 bytes total. |
|---|
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.
| MAC header | IP header | UDP header | BOOTP header | BOOTP/DHCP option | Data ::: |
| MAC header | IP header | UDP header | DHCP header | BOOTP/DHCP option | Data ::: |
BOOTP/DHCP option 1:
| 00 | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Code | Length | Mask ::: | |||||||||||||||||||||||||||||
Code.
8 bits.
Always set to 1.
Option code.
Length.
8 bits.
Always set to 4.
Size of the option data in bytes.
Mask.
32 bits.
Subnet mask of the client.
RFCs:
[RFC 2132] DHCP Options and BOOTP Vendor Extensions.
Obsolete RFCs:
[RFC 1533] DHCP Options and BOOTP Vendor Extensions.