Lectures notes for 2010 - KTH

BOOTP: Bootstrap Protocol (RFC 951)
Although you can figure out who you are, i.e., your IP address, via RARP - many
machines want more information.
BOOTP requests and answer are sent via UDP (port 67 server; port 68 client)
• so it is easy to make a user space server
• the client (who wants the answer) need not have a full TCP/IP, it can simply send what looks
like a UDP datagram with a BOOTP request 1 .
Opcode (1=request,
2=reply)
hardware type
(1=ethernet)
number of seconds
hardware address length hop count
(6 for ethernet)
transaction ID
unused
client IP address
your IP address
server IP address
gateway IP address
client hardware address (16 bytes of space)
server hostname (64 bytes)
Boot file name (128 bytes)
Vendor specific information (64 bytes)
1. see Stevens, Vol. 1, figure 16.2, pg. 216
Maguire BOOTP: Bootstrap Protocol (RFC 951) 4: 30 of 74
maguire@kth.se 2010.03.21 Internetworking/Internetteknik