Avaya Configuring SNMP, BOOTP, DHCP, and RARP Services Uživatelský manuál stáhnout pdf (Strana 40)

Configuring SNMP, BootP, DHCP, and RARP Services

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303542-A Rev 00

BootP Relay Agent Overview

BootP is built on the client-server model and allows a diskless client to boot

remotely from a server on the same network or on a different physical network.

The client broadcasts a request to boot from a remote server. When a suitable

server receives the BOOTREQUEST packet, it responds to the client by issuing a

BOOTREPLY packet, which includes the client’s IP address, the address of the

gateway, and the address of a server. The server then transmits the boot file to the

client via a transfer protocol, such as Trivial File Transfer Protocol (TFTP).

Figure 2-4 illustrates how BootP works when the client and the server are on the

same network. The client transmits a BOOTREQUEST packet to the IP broadcast

address (255.255.255.255). The server sends a BOOTREPLY packet to the client.

Depending on the server’s implementation, the server addresses the packet to

either the broadcast or the client’s IP address.

Figure 2-2. BootP Client and Server on the Same Physical Network

If, however, the client and the server are on different physical networks, a BootP

relay agent (also known as a BootP gateway) must forward BootP packets to their

correct destinations. When you configure a Bay Networks router for BootP

services, the router acts as a BootP relay agent. Figure 2-3

illustrates how BootP

works when the client and the server are on different physical networks.

Server sends acknowledgment

to the client (BOOTREPLY).

Client broadcasts a request

to boot from a remote server

(BOOTREQUEST).

Client Server

SNM0002A

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Avaya Configuring SNMP, BOOTP, DHCP, and RARP Services Uživatelský manuál Strana 40