| DRARP, Dynamic RARP |
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Description | Glossary | RFCs | Publications | Obsolete RFCs |
| Protocol suite: | TCP/IP. |
| Protocol type: | Network layer address resolution protocol. |
| Ethertype: | 0x8035. |
| Base protocol: | RARP, Reverse Address Resolution Protocol. |
| SNMP MIBs: | |
| Working groups: | |
| Links: |
DRARP is an extension of the RARP protocol that was used by some Sun Microsystems platforms beginning in 1988.
All Dynamic RARP servers are also RARP servers. However, DRARP provides a more manageable service model than RARP does: while RARP allows multiple servers to respond to RARP requests, it does not expect all those servers to be able to respond, or to respond identically. A given RARP server can not be relied upon to know whether a given link level address can be mapped into a protocol address, and some other RARP server may have a different answer. Dynamic RARP addresses this problem by requiring that all Dynamic RARP servers on a network segment must communicate with the same address authority. That address authority controls name and address bindings, records bindings between host identifiers and addresses, makes decisions about how to allocate addresses, and keeps records about addresses in use.
| MAC header | DRARP message |
DRARP message:
| 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Hardware type | Protocol type | ||||||||||||||||||||||||||||||
| Hardware address length | Protocol address length | Opcode | |||||||||||||||||||||||||||||
| Source hardware address ::: | |||||||||||||||||||||||||||||||
| Source protocol address ::: | |||||||||||||||||||||||||||||||
| Destination hardware address ::: | |||||||||||||||||||||||||||||||
| Destination protocol address ::: | |||||||||||||||||||||||||||||||
Hardware type. 16 bits.
| Value | Description |
|---|---|
| 1 | Ethernet. |
| 2 | Experimental Ethernet. |
| 3 | Amateur Radio AX.25. |
| 4 | Proteon ProNET Token Ring. |
| 5 | Chaos. |
| 6 | IEEE 802. |
| 7 | ARCNET. |
| 8 | Hyperchannel. |
| 9 | Lanstar. |
| 10 | Autonet Short Address. |
| 11 | LocalTalk. |
| 12 | LocalNet (IBM PCNet or SYTEK LocalNET). |
| 13 | Ultra link. |
| 14 | SMDS. |
| 15 | Frame Relay. |
| 16 | ATM, Asynchronous Transmission Mode. |
| 17 | HDLC. |
| 18 | Fibre Channel. |
| 19 | ATM, Asynchronous Transmission Mode. |
| 20 | Serial Line. |
| 21 | ATM, Asynchronous Transmission Mode. |
| 22 | MIL-STD-188-220. |
| 23 | Metricom. |
| 24 | IEEE 1394.1995. |
| 25 | MAPOS. |
| 26 | Twinaxial. |
| 27 | EUI-64. |
| 28 | HIPARP. |
| 29 | IP and ARP over ISO 7816-3. |
| 30 | ARPSec. |
| 31 | IPsec tunnel. |
| 32 | Infiniband. |
Protocol type. 16 bits.
| Value | Description |
|---|---|
| 0x800 | IP. |
Hardware address length.
8 bits.
Length of the hardware address in bytes.
Protocol address length.
8 bits.
Length of the protocol address in bytes.
Opcode. 8 bits.
| Value | Description | References |
|---|---|---|
| 3 | Request Reverse. | RFC 903 |
| 4 | Reply Reverse. | RFC 903 |
| 5 | DRARP Request. | RFC 1931 |
| 6 | DRARP Reply. | RFC 1931 |
| 7 | DRARP Error. | RFC 1931 |
Source hardware address. Variable length.
Source protocol address. Variable length.
Destination hardware address. Variable length.
Destination protocol address. Variable length.
RFCs:
[RFC 1931] Dynamic RARP Extensions for Automatic Network Address Acquisition.
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Description | Glossary | RFCs | Publications | Obsolete RFCs |