If installation mode was server:
# pkg info -r system/solaris-large-server
Name: group/system/solaris-large-server
Summary: Oracle Solaris Large Server
Description: Provides an Oracle Solaris large server environment
Category: Meta Packages/Group Packages
State: Installed
Publisher: solaris
Version: 0.5.11
Build Release: 5.11
Branch: 0.175.0.0.0.2.2576
Packaging Date: October 20, 2011 06:36:10 AM
Size: 5.45 kB
FMRI: pkg://solaris/group/system/solaris-large-server@0.5.11,5.11-0.175.0.0.0.2.2576:20111020T063610Z
Than ISC-DHCP is already installed:
# pkg info -r isc-dhcp
Name: service/network/dhcp/isc-dhcp
Summary: ISC DHCP Server and Relay Agent.
Description: ISC DHCP is open source software that implements the Dynamic
Host Configuration Protocols for connection to a local network.
This package includes the ISC DHCP server, relay agent and the
omshell tool.
Category: System/Services
State: Installed
Publisher: solaris
Version: 4.1.0.4
Build Release: 5.11
Branch: 0.175.0.6.0.2.0
Packaging Date: March 17, 2012 01:04:34 AM
Size: 7.51 MB
FMRI: pkg://solaris/service/network/dhcp/isc-dhcp@4.1.0.4,5.11-0.175.0.6.0.2.0:20120317T010434Z
But if it was uninstalled or installation mode was desktop (on X86), then:
# pkg install isc-dhcp
