B-4
User Guide for Cisco Network Registrar, 7.1
OL-16002-01
Appendices, Glossary, and Index
Appendix B DHCP Options
Option Descriptions
IP Layer Parameters Per Interface
lists the options that affect the operation of the IP layer on a per-interface basis. A client can
issue multiple requests, one per interface, to configure interfaces with their specific parameters.
Link Layer Parameters Per Interface
lists the options that affect the operation of the data link layer on a per-interface basis.
Table B-3
IP Layer Parameters Per Interface Options
Option Name
No. Length
Description
Interface MTU
26
2 octets
Maximum time to live to use on this interface.
All Subnets
Are Local
27
1 octet
Specifies whether or not the client can assume that all
subnets of the IP network to which the client is connected
use the same MTU as the subnet of that network to which the
client is directly connected.
Values: 1=all subnets share same MTU; 0=some
directly-connected subnets can have smaller MTUs
Broadcast
Address
28
4 octets
Broadcast address in use on the client subnet.
Perform Mask
Discovery
29
1 octet
Specifies whether or not the client should perform subnet
mask discovery using ICMP. Values: 0=disable; 1=enable
Mask Supplier
30
1 octet
Specifies whether or not the client should respond to subnet
mask requests using ICMP.
Values: 0=do not respond; 1=respond
Perform Router
Discovery
31
1 octet
Specifies whether or not the client should solicit routers
using the Router Discovery mechanism defined in RFC
1256. Values: 0=disable; 1=enable
Router
Solicitation
Address
32
4 octets
Address to which the client should transmit router
solicitation requests.
Static Route
33
8 octet minimum;
multiples of 8
List of static routes that the client should install in its
routing cache. If multiple routes to the same destination are
specified, they are in descending order of priority. The
routes consist of a list of IP address pairs. The first address
is the destination address, and the second address is the
router for the destination. The default route (0.0.0.0) is an
illegal destination for a static route.
Table B-4
Link Layer Parameters Per Interface Options
Option Name
No. Length
Description
Trailer
Encapsulation
34
1 octet
Specifies whether or not the client should negotiate the use of trailers
(RFC 893) when using the ARP protocol. Values: 0=do not use; 1=use
