TCP/IP Information
Copyright © 1997 by International Business Machines Corporation

DDNS Server Administrator Help

Dynamic Options Notebook

Use the Dynamic Options Notebook to customize your dynamic domain.

The Dynamic Options Notebook is displayed when you click the Dynamic Options push button on the Domain Configuration tab of the Primary Domain Notebook.

The Dynamic Options Notebook has these fields and check boxes:

Security Mode
Specifies whether this domain is in secured or presecured mode. In either mode, IBM DDNS servers use RSA public key digital signatures to authenticate DDNS update requests.

Client automatically creates its own host name
Sets secured mode, in which a DDNS server allows any host that complies with the DDNS protocol to register and update its host name.

Only system administrator can create client's host name
Sets presecured mode, in which a system administrator must preregister host names before hosts can dynamically update their records. To generate keys, click the Generate Keys for Host push button.

Include key and signature information when transferring data to secondary name servers
When checked, indicates that KEY and SIG records, which are used only in dynamic domains, are to be transferred to the secondary name servers for the domain.

Save copy of data before each update
When checked, indicates that the DDNS server is to create a backup copy of its dynamic domain data file before each update. All changes except those associated with the most recent update are backed up. If you have chosen to separate the static and dynamic data, only the dynamic data is backed up.

Delete SIG records for expired host names
When checked, specifies that a host's SIG records are to be removed when its name (KEY resource record) expires. For secured domains, all SIG records for the host will be deleted. For presecured domains, all SIG records corresponding to a host's resource records, except for the SIG KEY resource record, will be deleted. If not checked, SIG records remain indefinitely.

Note:

A SIG record holds an RSA digital signature, which is included in a dynamic update to the DDNS server. There is one SIG record for each type of resource record. The DDNS server uses the SIG record along with a host's KEY record to verify that the originator of an update message is really the owner of a resource targeted by the update message.

Delete every day at
Specifies the hour, in 24-hour time, when the SIG records are to be removed from the data base. The default is 2 am.

Adjust for client and server clock differences in determining data expiration times
When checked, specifies client/server time synchronization, in which the name server calculates an adjusted data expiration time based on the length of time requested by a client rather than the absolute time specified by the client. This option ensures the accuracy of the client-specified data expiration time when client and server clock settings are not identical or when clients and servers reside in different time zones.

Forward adjusted expiration time when transferring data to secondary name servers
When checked, specifies that the adjusted data expiration time (calculated by the name server) is to be forwarded to the secondary servers or to programs that request it, such as NSLOOKUP, which displays the adjusted data expiration time whenever a query is received for a host in this dynamic domain.

Set a maximum time to cache dynamic data for this domain
When checked, specifies that a maximum time for caching dynamic data on caching servers is to override all cache times specified elsewhere, such as in a client record. This option enables the administrator to reduce the cache times for dynamically entered records.

Note:

The cache times specified elsewhere are not changed.

Maximum time
Specifies the maximum amount of time, in seconds, that the dynamic data for this domain is to be cached on caching servers. If the value specified here is greater than a value specified elsewhere, the other (lower) value is used.

These push buttons are available in the Dynamic Options Notebook:

Generate keys for hosts
Displays the Generate Keys Window to enable you to generate keys for hosts in a domain running in presecured mode.
OK
Retains the configuration data in this notebook and closes the notebook.
Cancel
Cancels any actions taken in this notebook and closes the notebook.
Help
Displays information about the current notebook page.


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