HP OpenVMS Systems Documentation
Compaq TCP/IP Services for OpenVMS
The .DDNSKEYS file describes each DNS domain and the DNS name server that is to receive Host/IP address update information when DHCP distributes an address to a DHCP client in the domain. The information in this file consists of the domain to be updated and the IP address of the DNS server to which DHCP sends the updates. A third field for secure dynamic updates is reserved for future use. TCP/IP Services does not support secure dynamic updates.
The following example shows the contents of a typical .DDNSKEYS file:
$ TYPE PINE$DKB0:[DHCP_CONFIG].DDNSKEYS compaq.com 10.10.2.14 10.10.in-addr.arpa 10.10.2.14
Table 7-4 describes the command files used by the DHCP server.
|Command File Name||Description|
|TCPIP$DHCP_SETUPCOMMANDS.COM||Defines symbols to invoke DHCP utilities. It is located in the SYS$MANAGER: directory.|
|TCPIP$DHCP_STARTUP.COM||DCL commands to start the DHCP server.|
|TCPIP$DHCP_CLUSTER_STARTUP.COM||DCL commands to start the DHCP server in a cluster failover configuration.|
|TCPIP$DHCP_SHUTDOWN.COM||DCL commands to stop the DHCP server.|
|TCPIP$DHCP_CLUSTER_SHUTDOWN.COM||DCL commands to stop DHCP server in a cluster failover configuration.|
|TCPIP$DHCP_RUN.COM||Command procedure for starting DHCP server during the startup of DHCP server.|
|TCPIP$DHCP_SYSTARTUP.COM||Site-specific definitions and parameters to be invoked when DHCP starts.|
|TCPIP$DHCP_SYSHUTDOWN.COM||Site-specific definitions and parameters to be invoked when DHCP is shut down.|
By establishing logical names, you can modify the following server characteristics:
Table 7-5 lists the DHCP logical names and describes their function.
If defined, places the following DHCP files (during TCPIP$CONFIG) in
the directory you specify:
Setting this logical name is useful when you want to move the file location off the system disk or when you want to set up a DHCP cluster failover environment (see Section 7.4.5). The logical name must be defined before running TCPIP$CONFIG.
If not defined, the preceding DHCP-related files are placed in SYS$SYSDEVICE:[TCPIP$DHCP] during the TCPIP$CONFIG procedure.
|TCPIP$DHCP_DEBUG value||Logs full diagnostics. Valid numeric values are 1 to 6. If you define this logical, the value of TCPIP$DHCP_LOG_LEVEL is ignored.|
Defines the name of the DHCP server log file. The default is
If defined, each time the auxiliary server starts a DHCP server process, two log files are created: the one you define with TCPIP$DHCP_LOG name and the default TCPIP$DHCP_RUN.LOG.
Writes the specified level of diagnostic information to the log file.
Ignored if TCPIP$DHCP_DEBUG is defined.
Valid numeric values are:
You define system wide TCPIP$DHCP logical names in the SYS$STARTUP:TCPIP$DHCP_SYSTARTUP.COM file. After making changes to the file, enter the following commands:
$ @SYS$STARTUP:TCPIP$DHCP_SHUTDOWN.COM $ @SYS$STARTUP:TCPIP$DHCP_STARTUP.COM
Alternatively, you can follow these steps:
The DHCP server creates a log file named TCPIP$DHCP_RUN.LOG in the
7.3 DHCP Server Startup and Shutdown
The DHCP server can be shut down and started independently of TCP/IP Services. This is useful when you change parameters or logical names that require the service to be restarted.
The following files are provided:
To preserve site-specific parameter settings and commands, create the following files. These files are not overwritten when you reinstall TCP/IP Services:
If you specified automatic startup during the TCP/IP Services configuration procedure (TCPIP$CONFIG), the DHCP server process starts automatically when the DHCP service is started (TCPIP$DHCP_STARTUP.COM).
Be aware that a new DHCP server process starts automatically as soon as the old process exits unless you disable the DHCP service before entering a DHCPSIGTERM command. As an alternative method, you can shut down DHCP by executing the following command:
Because the DHCP server has several binary databases open (updates to which might not have been flushed to the disk), do not stop a running DHCP process using the DCL command STOP/ID=entry_number. Instead, stop the DHCP process by entering the DHCPSIGTERM command.
7.4 Configuring the DHCP Server
To configure the DHCP server, perform the following tasks:
|Enable DHCP on your system and set up DHCP files and databases.||Section 7.4.1|
|Set up DNS/BIND.||Section 7.4.2|
|Set up the cluster failover environment.||Section 7.4.5|
|Stop the DHCP process.||Section 7.3.1|
|Shut down and start up the DHCP process.||Section 7.3|
|Configure client information (use the DHCP GUI or make changes manually).||Section 7.5 or Section 7.7, respectively|
|Set up the NETMASKS. file, if appropriate.||Section 188.8.131.52|
|Define IP addressing.||Section 7.6|
To enable DHCP initially, run the TCPIP$CONFIG procedure by entering the following command and then choose DHCP from the Server Components menu:
The configuration procedure asks if you want to convert existing BOOTP entries to DHCP database:
Do you want to rollover old-style BOOTP entries into the DHCP database? [Y]
Name of file to use for old-style BOOTP: SYS$SYSTEM:TCPIP$BOOTP.DAT Press return or enter new file name:
Compaq recommends calling the TCPIP$DHCP_SETUPCOMMANDS.COM procedure as part of the login process for all users who are authorized to manage the DHCP server.
DHCP uses the following methods to assign a host name:
To configure DHCP to assign a host name dynamically, perform the following steps:
To configure DHCP to use host names defined in a DNS/BIND server database, perform the following steps:
One of the DHCP utilities that is defined in TCPIP$DHCP_SETUPCOMMANDS.COM is the TCPIP$DHCP_SIGNAL utility, which provides interprocess signaling in a manner similar to the UNIX kill signal delivery utility. PRMMBX and SYSNAM privileges are required to run TCPIP$DHCP_SIGNAL.EXE.
The following table shows the commands available with the TCPIP$DHCP_SIGNAL utility:
|DHCPSIGHUP||Causes the ASCII configuration files to be read again, flushes the binary databases and then translates the TCPIP$DHCP_DEBUG and TCPIP$DHCP_LOG_LEVEL logical names.|
|DHCPSIGTERM||Causes an orderly shutdown of DHCP.|
|DHCPSIGUSR1||Causes a dump of the ASCII configuration files, then flushes the binary databases.|
You can return to a BOOTP-only configuration at any time. Further, you can use the previous TCPIP$BOOTP.DAT database file and the client entries it contains. If you deleted the TCPIP$BOOTP.DAT file, you can create a new one and populate it with entries (see Section 9.5).
To enable BOOTP after you have configured your host for DHCP, run
TCPIP$CONFIG and enable the BOOTP component from the Server Components
menu. Your existing DHCP files will remain for future use.
7.4.5 Setting Up a DHCP Cluster Failover Environment
You can set up an OpenVMS Cluster environment for DHCP server failover. In this environment, a standby system becomes the DHCP server if the active DHCP server process fails or is stopped, or the system on which it is running fails or shuts down.
With cluster failover, the DHCP server uses the OpenVMS lock manager during process initialization to acquire a system-level, exclusive-mode lock on a resource called TCPIP$DHCP_SERVER. The first server started on the cluster obtains the lock on TCPIP$DHCP_SERVER and becomes the active DHCP server. The other DHCP servers wait to obtain the lock and become the standby servers.
When the active DHCP server process exits for any reason, the lock on TCPIP$DHCP_SERVER is released and one of the standby processes acquires the lock and becomes the active server.
To configure the DHCP server failover environment, do the following:
$ CREATE/DIRECTORY/OWNER=TCPIP$DHCP WORK1$:[DHCP_CONFIG]
$ COPY SYS$SYSDEVICE:[TCPIP$DHCP]DHCPCAP. TCPIP$DHCP_CONFIG: $ COPY SYS$SYSDEVICE:[TCPIP$DHCP]DHCPTAGS. TCPIP$DHCP_CONFIG: $ COPY SYS$SYSDEVICE:[TCPIP$DHCP]NAMEPOOL. TCPIP$DHCP_CONFIG: $ COPY SYS$SYSDEVICE:[TCPIP$DHCP]NETMASKS. TCPIP$DHCP_CONFIG: $ COPY SYS$SYSDEVICE:[TCPIP$DHCP]NETS. TCPIP$DHCP_CONFIG: $ COPY SYS$SYSDEVICE:[TCPIP$DHCP]SERVER.PCY TCPIP$DHCP_CONFIG: $ COPY SYS$SYSDEVICE:[TCPIP$DHCP]DB%.%%% TCPIP$DHCP_CONFIG: $ COPY SYS$SYSDEVICE:[TCPIP$DHCP].DDNSKEYS TCPIP$DHCP_CONFIG:
$ CREATE/DIR SYS$SYSDEVICE:[TCPIP$DHCP.SAVE] $ PURGE SYS$SYSDEVICE:[TCPIP$DHCP] $ RENAME SYS$SYSDEVICE:[TCPIP$DHCP]DHCPCAP.;* SYS$SYSDEVICE:[TCPIP$DHCP.SAVE] $ RENAME SYS$SYSDEVICE:[TCPIP$DHCP]DHCPTAGS.;* SYS$SYSDEVICE:[TCPIP$DHCP.SAVE] $ RENAME SYS$SYSDEVICE:[TCPIP$DHCP]NAMEPOOL.;* SYS$SYSDEVICE:[TCPIP$DHCP.SAVE] $ RENAME SYS$SYSDEVICE:[TCPIP$DHCP]NETMASKS.;* SYS$SYSDEVICE:[TCPIP$DHCP.SAVE] $ RENAME SYS$SYSDEVICE:[TCPIP$DHCP]NETS.;* SYS$SYSDEVICE:[TCPIP$DHCP.SAVE] $ RENAME SYS$SYSDEVICE:[TCPIP$DHCP]SERVER.PCY;* SYS$SYSDEVICE:[TCPIP$DHCP.SAVE] $ RENAME SYS$SYSDEVICE:[TCPIP$DHCP]DB%.%%%;* SYS$SYSDEVICE:[TCPIP$DHCP.SAVE] $ RENAME SYS$SYSDEVICE:[TCPIP$DHCP].DDNSKEYS;* SYS$SYSDEVICE:[TCPIP$DHCP.SAVE]
$ DEFINE/SYSTEM TCPIP$DHCP_CONFIG WORK1$:[DHCP_CONFIG]
$ DIRECTORY/SECURITY WORK1$:[DHCP_CONFIG] $ DIRECTORY/SECURITY WORK1$:DHCP_CONFIG.DIR
184.108.40.206 220.127.116.11 18.104.22.168-22.214.171.124
126.96.36.199 0.0.0.0 188.8.131.52-184.108.40.206