The dhcptab ConfigurationTable

The dhcptab table contains information related to client configuration. The table is organized as a series of macro definitions that contain all of the information necessary to configure a network client. A client gets its configuration when it is assigned an IP address from the network table. The macro name associated with the IP address corresponds to a macro name in the dhcptab table. After a client gets an IP address from the network table, it gets its network configuration from the dhcptab table.

During the initial configuration of the DHCP server, the dhcptab table is created with macros for each configured network. Each of these macros contains information specific to the network, including subnet mask, network broadcast address, IP packet time to live, maximum datagram size, default router, static routes, DNS domain, NIS domain, DNS servers, and NIS servers, if these are available when the server is configured.

You can control how client machines access a network by changing the information contained in the macros. For example, changing the name of the macro that a particular client machine uses changes the network configuration of that machine. In a different example, changing a single option within a macro changes the reactions of all the machines that use that macro set. The ability to manage IP addresses is one of the major features of DHCP. The dhtadm command manages the dhcptab server configuration table. Example 16-2 shows an example of dhtadm output.

Example 16-2 Sample Output: dhtadm -P

Name         Type    Value

mrcoffee     Macro  :Subnet=255.255.255.0:Router=129.146.86.1:Broadcst=129.146.86.255: \
                    :BootSrvA=129.146.86.175:BootFile="/export/root/JavaDesktop/kona": \
                    :NISservs=129.146.86.33:NISdmain=sunsoft.eng.sun.com: \
                    :DNSdmain=Eng.Sun.COM: \
                    :DNSserv=129.146.1.151 129.146.1.152 129.144.1.57 129.144.134.19: \ 
                    :Include=Locale: \
                    :Timeserv=129.144.1.3:LeaseTim=3600:T1Time=1800: \
                    :T2Time=3060:	

Locale       Macro  :UTCoffst=25200:SN_TZ="PST8PDT":

inet11       Macro  :Include=Locale:Timeserv=129.146.86.181:LeaseTim=259200: \
                    :DNSdmain=Eng.Sun.COM: \
                    :DNSserv=129.146.1.151 129.146.1.152 129.144.1.57 129.144.134.19:

hobbs        Macro  :Subnet=255.255.255.0:Router=129.146.86.1:Broadcst=129.146.86.255: \
                    :BootSrvA=129.146.86.32:BootFile="819256D6.PREP":

129.146.89.0 Macro  :Subnet=255.255.255.0:Router=129.146.89.1:Broadcst=129.146.89.255: \
                    :NISdmain=sunsoft.eng.sun.com:NISservs=129.146.89.33: \
                    :NetBNms=129.146.171.31:NetBNdT=8:

129.146.88.0 Macro  :Subnet=255.255.255.0:Router=129.146.88.1:Broadcst=129.146.88.255: \
                    :NISdmain=sunsoft.eng.sun.com:NISservs=129.146.88.33: \
                    :NetBNms=129.146.171.31:NetBNdT=8:

129.146.87.0 Macro  :Subnet=255.255.255.0:Router=129.146.87.1:Broadcst=129.146.87.255: \
                    :NISdmain=sunsoft.eng.sun.com:NISservs=129.146.87.33: 
                    :NetBNms=129.146.171.31:NetBNdT=8:	

129.146.86.0 Macro  :Broadcst=129.146.86.255:Subnet=255.255.255.0:MTU=1500: \
                    :Router=129.146.86.1:NISdmain=sunsoft.eng.sun.com: \
                    :NISservs=129.146.86.33:NetBNms=129.146.171.31:NetBNdT=8: \
                    :BootSrvA=129.146.86.32:

129.146.85.0 Macro  :Subnet=255.255.255.0:Router=129.146.85.1:Broadcst=129.146.85.255: \
                    :NISdmain=sunsoft.eng.sun.com:NISservs=129.146.85.33: \
                    :NetBNms=129.146.171.31:NetBNdT=8:

129.146.84.0 Macro  :Subnet=255.255.255.0:Router=129.146.84.1:Broadcst=129.146.84.255: \
                    :NISdmain=sunsoft.eng.sun.com:NISservs=129.146.84.33: \
                    :NetBNms=129.146.171.31:NetBNdT=8:

129.146.83.0 Macro  :Subnet=255.255.255.0:Router=129.146.83.1:Broadcst=129.146.83.255: \
                    :NISdmain=sunsoft.eng.sun.com: \
                    :NISservs=129.146.83.33:NetBNms=129.146.171.31:NetBNdT=8:

129.146.82.0 Macro  :Subnet=255.255.255.0:Router=129.146.82.1:Broadcst=129.146.82.255: \
                    :NISdmain=sunsoft.eng.sun.com:NISservs=129.146.82.33: \
                    :NetBNms=129.146.171.31:NetBNdT=8:

129.146.81.0 Macro  :Subnet=255.255.255.0:Router=129.146.81.1:Broadcst=129.146.81.255: \
                    :NISdmain=sunsoft.eng.sun.com:NISservs=129.146.81.33: \
                    :NetBNms=129.146.171.31:NetBNdT=8:

SN_TZ        Symbol Vendor=SUNW,13,ASCII,1,0