Unformatted text preview: tP - Message Fields
Returned in boot reply by server Router IP-address
Server is part of another Subnet
IP-address of the BootP relay Client Hardware-address
MAC-address of client (C) Herbert Haas 2005/03/11 12 The "Server-IP-address" contains the IP address of an optional boot server.
If a gateway does decide to forward the request, it should look at the 'giaddr'
(gateway IP address) field. If zero, it should plug its own IP address (on the
receiving cable) into this field. It may also use the 'hops' field to optionally
control how far the packet is reforwarded. Hops should be incremented on each
forwarding. For example, if hops passes '3', the packet should probably be
The Client's HW address is needed to find an entry in the address-table at the
BOOTP server. 12 BootP - Message Fields
Server Host Name
Optional server host name Bootfilename
Contains directory path and filename of the
bootfile Vendor Specific Area
Optionally contain vendor information of the
RFC 1048: also possible to mention the subnet
mask, hostname, domain name, DNS, etc (C) Herbert Haas 2005/03/11 13 Optionally, the servers domain name can be specified. This field is limited to 64
The "Bootfilename" contains the directory path and filename of the bootfile,
which is located at the server specified above. 13 Dynamic Host Configuration Protocol (DHCP) A dynamic solution with even more parameters (C) Herbert Haas 2005/03/11 14 14 Principles
Nearly identical to BOOTP
Slightly extended messages only
More parameters Uses UDP communication
Client-Side: Port 67
Server-Side: Port 68 Based on a leasing idea!
Dynamic configuration RFC 2131 and RFC 2132 (C) Herbert Haas 2005/03/11 15 The Dynamic Host Configuration Protocol works nearly identical to BOOTP.
DHCP uses the same message format with only slightly chances.
DCHP based on a leasing idea. The IP address will be leased from the server to
the client for a special time, after this time expired the client need to send his
request again. 15 Flexible Confi...
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- Spring '14
- Computer Networks, IP address, Dynamic Host Configuration Protocol, Herbert Haas