B-8
User Guide for Cisco Network Registrar, 7.1
OL-16002-01
Appendices, Glossary, and Index
Appendix B DHCP Options
Option Descriptions
DHCPv4 Extension Options
lists the DHCPv4 extension options.
Finger Server
73
4 octet minimum;
multiples of 4
List of Finger servers available to the client. Servers
should be in order of preference.
Internet Relay
Chat Server
74
4 octet minimum;
multiples of 4
List of IRC servers available to the client. Servers should
be in order of preference.
StreetTalk
Server
75
4 octet minimum;
multiples of 4
List of StreetTalk servers available to the client. Servers
should be in order of preference.
StreetTalk
Directory
Assistance
(STDA) Server
76
4 octet minimum;
multiples of 4
List of STDA servers available to the client. Servers should
be in order of preference.
Table B-6
Application and Service Parameter Options (continued)
Option Name
No. Length
Description
Table B-7
DHCPv4 Extensions
Option Name
No. Length
Description
Requested IP
Address
50
4 octets
Used in a client request (DHCPDISCOVER) to allow the client to
request that a particular IP address be assigned.
IP Address
Lease Time
51
4 octets
Used in a client request (DHCPDISCOVER or DHCPREQUEST)
to allow the client to request a lease time for the IP address. In a
server reply (DHCPOFFER), a DHCP server uses this option to
specify the lease time it is willing to offer.
Value: seconds, as 32-bit unsigned integer
Option Overload 52
1 octet
Indicates that the DHCP sname or file fields are being overloaded
by using them to carry DHCP options. A DHCP server inserts this
option if the returned parameters will exceed the usual space
allotted for options. If this option is present, the client interprets
the specified additional fields after it concludes interpretation of
the standard option fields.
Values: 1=file field is used to hold options; 2=sname field is used
to hold options; 3=both fields are used to hold options
DHCP Message
Type
53
1 octet
Used to convey the type of DHCP message. The preset value is 1
(DHCPDISCOVER). Values:
1=DHCPDISCOVER; 2=DHCPOFFER; 3=DHCPREQUEST;
4=DHCPDECLINE; 5=DHCPACK; 6=DHCPNAK;
7=DHCPRELEASE; 8=DHCPINFORM; 13=LEASEQUERY
