![]() |
![]() HP OpenVMS Systems Documentation |
![]() |
HP TCP/IP Services for OpenVMS
|
Previous | Contents | Index |
To add a new server and enable the BIND resolver, enter the following command:
TCPIP> SET NAME_SERVICE /SERVER=host /ENABLE /SYSTEM |
For host, specify the host name or IP address of the BIND server or servers that the BIND resolver is to query.
To specify multiple hosts, list them by request preference. The BIND resolver sends the first lookup request to the first host on the list.
If you define a server list and then add a new server with the SET NAME_SERVICE /SERVER command, the new server is added to the end of the list.
SET commands affect the volatile database. To save your changes to the permanent database, use the SET CONFIGURATION commands. The changes you make with the SET CONFIGURATION commands take effect the next time the software starts up. For example:
TCPIP> SET CONFIGURATION NAME_SERVICE /SERVER=host /ENABLE |
TCPIP> SHOW CONFIGURATION NAME_SERVICE BIND Resolver Configuration Transport: UDP Domain: ucx.ern.sea.com Retry: 4 Timeout: 4 Servers: 9.20.208.47, 9.20.208.53 Path: No values defined |
The following command defines hosts PARROT, SORA, and JACANA as systemwide BIND servers and enables the BIND resolver:
PARROT> TCPIP TCPIP> SET NAME_SERVICE /SERVER=(PARROT,SORA,JACANA) /SYSTEM /ENABLE |
The following example defines, for the current login session, host OSPREY as the BIND server. As a result, the servers that are defined systemwide are not queried.
TCPIP> SET NAME_SERVICE /SERVER=OSPREY |
By default, if no search list is defined and the host name as you typed it has no dot (.) in the name, the BIND resolver performs a lookup using the following forms of the host name:
For example, suppose you enter the command:
TCPIP> SHOW HOST OWL |
Assuming that the default domain is ucx.ern.sea.com , the resolver performs lookups as follows:
This behavior is different than the resolver lookup behavior in
previous releases (UCX BIND Version 4.x.). The following
section provides more information.
D.7.4 Resolver Search Behavior in Earlier Releases
In previous releases, the resolver performed lookups as follows:
For each unsuccessful lookup, this procedure was repeated until only two labels remained in the resulting domain name.
If all these attempts failed, the resolver tried just the host name as typed (as long as it contained at least one dot).
For example, suppose you entered the command:
TCPIP> SHOW HOST OWL |
Assuming the default domain was ucx.ern.sea.com , the resolver performed lookups as follows:
The search list is provided to make entering lookup commands easier by not requiring you to type fully qualified domain names. The search list consists of domain names that the resolver uses when performing lookups. By default, the search list consists of only the default domain, which is stored in the TCPIP$CONFIGURATION.DAT file.
You can change the elements in the search list by entering the SET NAME_SERVICE command, as shown in the following example:
TCPIP> SET NAME_SERVICE /PATH=(ucx.ern.sea.com,dux.sea.com,mux.ern.sea.com)/SYSTEM |
For example, if you enter the command:
TCPIP> SHOW HOST CANARY |
The resolver performs lookups in the following sequence:
In the following output of the SHOW NAME_SERVICE command, the PATH: label shows the search list information entered with the SET NAME_SERVICE /PATH command. This command displays systemwide information and process-specific information (if process-specific information is set).
TCPIP> SHOW NAME_SERVICE BIND Resolver Parameters Local domain: ucx.ern.sea.com System State: Started, Enabled Transport: UDP Domain: ucx.ern.sea.com Retry: 4 Timeout: 4 Servers: ucx, lemng, 16.99.0.10 Path: ucx.ern.sea.com, dux.ern.sea.com, mux.ern.sea.com Process State: Enabled Transport: Domain: Retry: Timeout: Servers: Path: $ |
Any additions you make are appended to the end of the search list.
To remove an element from the search list, enter the following command:
TCPIP> SET NAME_SERVICE /NOPATH=dux.ern.sea.com /SYSTEM |
When you execute TCPIP$CONFIG.COM after upgrading from UCX to TCP/IP Services for OpenVMS, the system creates a domain search list that is consistent with the UCX default lookup behavior. TCPIP$CONFIG.COM uses the default domain to create a search list consisting of each parent domain. For example, if the default domain is ucx.ern.sea.com , the resulting search list is ucx.ern.sea.com,ern.sea.com,sea.com . You can modify the current search list by using the SET CONFIGURATION NAME_SERVER /PATH command. |
NSLOOKUP is a debugging tool provided with BIND that allows anyone to directly query a name server and retrieve information. Use NSLOOKUP to determine whether your local name server is running correctly or to retrieve information from remote servers.
NSLOOKUP makes direct queries to name servers around the world to obtain DNS information, which includes:
Table D-12 shows how to start and stop NSLOOKUP.
Task | Command |
---|---|
Run NSLOOKUP. | $ RUN SYS$SYSTEM:TCPIP$NSLOOKUP.EXE |
Terminate NSLOOKUP from within interactive mode. | > EXIT |
Terminate the current NSLOOKUP session. | > Ctrl/Z |
To run NSLOOKUP as a foreign command, enter the following command at the DCL prompt ($), or place the command in your LOGIN.COM file:
$ NSLOOKUP :== SYS$SYSTEM:TCPIP$NSLOOKUP.EXE |
You can then run an interactive NSLOOKUP session by entering:
$ NSLOOKUP > |
You can put NSLOOKUP
set
commands in an initialization file named SYS$LOGIN:NSLOOKUPINIT.INI.
The commands are executed when you start NSLOOKUP.
D.8.2 Obtaining Help
You can obtain help by:
$ HELP TCPIP_SERVICES NSLOOKUP |
> ? |
> help |
The following example shows the information available with the NSLOOKUP help (?) command:
$ NSLOOKUP Default Server: condor.lgk.dec.com Address: 16.99.208.53 > ? Information available: <host> About_nslookup exit finger ls lserver root server set Topic? |
NSLOOKUP interprets unrecognized commands as host names. When using NSLOOKUP, apply these syntax rules:
When NSLOOKUP first starts, you see the name and address of the default BIND server, followed by the NSLOOKUP prompt. In the following example, the default server is condor.lgk.dec.com .
$ NSLOOKUP Default Server: condor.lgk.dec.com Address: 16.99.208.53 > |
Table D-13 lists the NSLOOKUP commands.
Command | Function |
---|---|
host [ server] |
Looks up information using the current default server or the server you
specify. Enter the name of the host for which you need an IP address.
For example, the following command searches for
www.whitehouse.gov
using the default server:
> www.whitehouse.gov The following command uses the server with IP address 128.45.45.40
to look up the host
snowy.frozen.weather.com
:
|
server domain |
Changes the default server to the domain you specify. The following
command changes the default server using the current default server to
look up information for the new default server, 128.45.35.40:
> server 128.45.35.40 |
lserver domain |
Changes the default server. The following command changes the default
server using the initial default server to find information about
128.45.35.40:
> lserver 128.45.35.40 |
root |
Changes the default server to the server specified by the root option.
> root |
ls |
Lists information about hosts in the domain you specify. The default
output contains host names and their IP addresses. The options for
ls
are listed in Table D-15.
The following example redirects the output from the screen to the
file
NSLOOKUP.temp
in the current directory.
|
help or ? | Displays a summary of the available commands. |
exit | Exits NSLOOKUP. |
set | Selects the type of information that NSLOOKUP displays. Table D-14 lists the available options. |
NSLOOKUP has options that influence the type of information you receive from a query and the way NSLOOKUP behaves. Some of the options take a value and others are Boolean options. The options have default values and can be changed by using the set command.
You obtain a list of the options and their default values by entering the set all command immediately after starting an interactive NSLOOKUP session, as shown in the following example:
$ NSLOOKUP Default Server: condor.lgk.dec.com (1) Address: 16.99.208.53 > set all (2) Default Server: condor.lgk.dec.com Address: 16.99.208.53 Set options: nodebug defname search recurse (3) nod2 novc noignoretc port=53 (4) querytype=A (5) class=IN timeout=4 retry=4 root=a.root-servers.net. domain=xyz.prq.dec.com (6) srchlist=xyz.prq.dec.com (7) > |
For a description of other set options, see Table D-14.
Option | Function | ||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
all |
Displays the current values of the options you can set as well as
information about the current default server. For example:
> set all |
||||||||||||||||||
class= value |
Changes the query class to one of the following:
The class specifies the protocol group of the information. You can use the abbreviated form of the keyword cl . The following command tells NSLOOKUP to resolve both internet and chaos class queries (you can enter INTERNET and CHAOS): > set class=ANY |
||||||||||||||||||
querytype |
Specifies the type of information you want. For example:
> set querytype=A Valid types include:
|
||||||||||||||||||
[no]debug |
Turns on debugging (default is
nodebug
). NSLOOKUP displays both detailed information about the packet sent to
the server and the answer. You can use the abbreviations
nodeb
and
deb
. For example:
> set debug |
||||||||||||||||||
[no]d2 |
Returns all-inclusive debugging information (default is
nod2
). Displays all the fields of every packet. For example:
> set d2 |
||||||||||||||||||
recurse |
Tells the BIND server to contact other servers if it does not have the
information you want. The servers carry out a complete (recursive)
resolution for each query. For example:
> set recurse |
||||||||||||||||||
retry |
Number of times that NSLOOKUP attempts to contact a BIND server if
repeated tries fail. For example:
> set retry=8 |
||||||||||||||||||
timeout |
Length of time (in seconds) to wait for a reply from each attempt. For
example:
> set timeout=9 |
||||||||||||||||||
root= value |
Changes the root server. For example, the following command changes the
root server to
ns.nasa.gov
.
> set root=ns.nasa.gov |
||||||||||||||||||
ignoretc |
Tells NSLOOKUP to ignore packet truncation errors. For example:
> set ignoretc |
||||||||||||||||||
domain name |
Changes the default domain to the domain you specify.
How the default domain name is appended to lookup requests depends on the settings of the defname and search options. The domain search list contains the parents of the default domain if it has at least two components in its name. The default value is set in the TCP/IP configuration database. To specify the default, type the abbreviation do . For example, if the default domain is CC.Berkeley.EDU , the search list is CC.Berkeley.EDU and Berkeley.EDU . |
||||||||||||||||||
srchlist | If set, NSLOOKUP appends each of the domain names specified in the srchlist option to an unqualified host name and performs a query until an answer is received. | ||||||||||||||||||
srchlist= names |
Changes the default domain name to the first name you specify and the
domain search list to all the names you specify. Specify a maximum of
six names separated by slashes (/).
In the following example, the command sets the default domain to lcs.MIT.EDU and the search list to the three specified domains. The command overrides the default domain name and associated search list for the set domain command. > set srchlist=lcs.MIT.EDU/ai.MIT.EDU/MIT.EDU The default is the domain name specified in the TCP/IP configuration database. The abbreviated form of the command is srchl . |
||||||||||||||||||
[no]defname |
Tells NSLOOKUP to append a default domain name to a not fully qualified
1 DNS name lookup request. The abbreviated form is
[no]def
.
For example, an NSLOOKUP query for the host rainy becomes rainy.cc.berkeley.edu . |
||||||||||||||||||
[no]search | Tells NSLOOKUP to append the domain names in the search list to a not fully qualified domain name 1 lookup request. The default is search . The abbreviated form is [no]sea . |
Previous | Next | Contents | Index |