| BOOTP/DHCP option 21, Policy Filter |
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Description | Glossary | RFCs | Publications | Obsolete RFCs |
| Protocol suite: | TCP/IP. |
| Protocol type: | Application layer configuration protocol. |
| Base protocols: |
BOOTP, Bootstrap Protocol. DHCP, Dynamic Host Configuration Protocol. |
| Option length: | 10+ bytes. |
| Links: | IANA: BOOTP and DHCP options. |
This option specifies policy filters for non-local source routing. The filters consist of a list of IP addresses and masks which specify destination/mask pairs with which to filter incoming source routes. Any source routed datagram whose next-hop address does not match one of the filters should be discarded by the client.
| MAC header | IP header | UDP header | BOOTP | DHCP header | BOOTP/DHCP option 21 |
BOOTP/DHCP option 21:
| 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 |
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| Code | Length | Address/mask pair [] ::: | |||||||||||||||||||||||||||||
Code.
8 bits.
Always set to 21.
Option code.
Length.
8 bits.
8+ in multiples of 8.
Size of the option data in bytes.
Address/mask pair. 8 bytes.
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 IP address Subnet mask IP address. 32 bits.
Subnet mask. 32 bits.
RFCs:
[RFC 2132] DHCP Options and BOOTP Vendor Extensions.
[RFC 1533] DHCP Options and BOOTP Vendor Extensions.
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Description | Glossary | RFCs | Publications | Obsolete RFCs |