Bootstrap Protocol: Difference between revisions

Revision as of 12:22, 20 November 2020

Revision as of 12:28, 20 November 2020

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==Operation==

Case 1 : Client and server on same network

; Case 1 : Client and server on same network

When a BOOTP client is started, it has no IP address, so it broadcasts a message containing its MAC address onto the network. This message is called a “BOOTP request,” and it is picked up by the BOOTP server, which replies to the client with the following information that the client needs:

When a BOOTP client is started, it has no IP address, so it broadcasts a message containing its MAC address onto the network. This message is called a “BOOTP requestrequest”,” and it is picked up by the BOOTP server, which replies to the client with the following information that the client needs:

1.# The client’s IP address, subnet mask, and default gateway address.

2.# The IP address and host name of the BOOTP server.

3.# The IP address of the server that has the boot image, which the client needs to load its operating system.

When the client receives this information from the BOOTP server, it configures and initializes its TCP/IP protocol stack, and then connects to the server on which the boot image is shared. The client loads the boot image and uses this information to load and start its operating system.<ref>{{cite web |url=https://networkencyclopedia.com/bootstrap-protocol-bootp/ |title=Bootstrap Protocol (BOOTP) |website=Network Encyclopedia}}</ref>

2. The IP address and host name of the BOOTP server

3. The IP address of the server that has the boot image, which the client needs to load its operating system

When the client receives this information from the BOOTP server, it configures and initializes its TCP/IP protocol stack, and then connects to the server on which the boot image is shared. The client loads the boot image and uses this information to load and start its operating system.

The Dynamic Host Configuration Protocol (DHCP) was developed as an extension of BOOTP. BOOTP is defined in Request for Comments (RFC) 951 and 1084.

; Case 2 : Client and server on different networks

Courtesy: https://networkencyclopedia.com/bootstrap-protocol-bootp/

Case 2 : Client and server on different networks

# Problem with the bootp request is that the request is broadcast. A [[IP_address#Broadcast_addressing|broadcast]] [[IP data-gramdatagram]] cannot pass through any router. The router discards this packet.

# To solve this problem, there is a need for an intermediary (relay).

# One of the host or router can be configured at application layer to operate as relay agent.

# The relay agent knows the uni-cast address of bootp server and listens for broadcast message on port 67.

# When it receives this broadcast packet, it encapsulates the message in uni-cast[[unicast]] data-gramdatagram and sends request to bootp server.

# The packet carrying a uni-castunicast destination address is routed by any router and reaches the bootp server.

# The relay agent, after receiving the reply, sends it to bootp client.

==IETF standards documentation==