by Matthew G. Naugle
Wiley Computer Publishing, John Wiley & Sons, Inc.
ISBN: 0471196568 Pub Date: 11/01/98
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Illustrated TCP/IP
by Matthew G. Naugle Wiley Computer Publishing, John Wiley & Sons, Inc. ISBN: 0471196568 Pub Date: 11/01/98 |
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| Field | Bytes | Description |
|---|---|---|
| op | 1 | Packet operation code/message type. 1 = BOOTREQUEST, 2 = BOOTREPLY |
| htype | 1 | Hardware address type, same as ARP section in “Assigned Numbers” RFC. For example, “1” = 10 Mb Ethernet. |
| hlen | 1 | Hardware address length. For example, “6” (bytes) for 10 Mb Ethernet. |
| hops | 1 | Client sets to 0 and optionally used by gateways in BOOTP Relay. |
| xid | 4 | Transaction ID. A random number used to match this boot request with the responses it generates. |
| secs | 2 | Filled in by the client, indicating the number of seconds that have elapsed since the client started trying to boot. |
| ciaddr | 4 | Client IP address; filled in by client in BOOTREQUEST, if known. |
| yiaddr | 4 | “Your” (client) IP address; filled in by the server if the client doesn’t know its own address (i.e., ciaddr was a 0). |
| siaddr | 4 | Server IP address, returned in the BOOTREPLY by the server. |
| giaddr | 4 | The gateway’s IP address of the port that received the first BOOTREQUEST. It is used in the BOOTREPLY function. |
| chaddr | 16 | The client’s hardware (MAC) address. It is filled in by the client. |
| sname | 64 | Optional. The server hostname being requested by the client. All other servers would then ignore this packet. |
| file | 128 | The boot filename. The ‘”generic” name in the BOOTREQUEST. |
| Vend | 64 | This is an optional vendor-specific field. Examples of its use could be a serial number, version number, etc. It is generally ignored by BOOTP. |
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