This Read Me document describes late-breaking information about your MacDNS software and updates to its documentation. You may want to print this document for future reference.
Product information
MacDNS 1.0.4 fixes some problems in MacDNS 1.0.3 and earlier versions, providing improved performance and reliability. Upgrading to version 1.0.4 is recommended for all MacDNS customers.
This version of MacDNS is available under the terms of a no-fee license. The license agreement appears the first time you open the MacDNS program. Click the Agree button to accept the terms of the agreement.
For additional information about MacDNS, refer to the MacDNS FAQ (Frequently Asked Questions) document, available on the Internet at the following URL:
http://cybertech.apple.com/dns/dns_faq.html
Hardware and software requirements
MacDNS 1.0.4 requires the following minimum system configuration:
- a Macintosh computer with at least a 68020 processor, or a PowerPC processor
- 1500K of free memory
- a TCP/IP network connection and IP address
- System 7.0 or later (System 7.5.3 recommended)
- MacTCP 2.0.6, or Open Transport 1.1 or later
Note: If you are running a system version prior to 7.5, you also need to install the Thread Manager 2.0.1 extension, available on the Internet at the following URL:
Open Transport networking software, version 1.1 or later, is recommended for use with MacDNS. (System 7.5.3 includes Open Transport version 1.1.) Look for information about system software updates and about the latest version of Open Transport on Apple forums and Apple Web sites on the Internet, including:
http://www.info.apple.com/
Configuring advanced MacDNS settings
MacDNS is preconfigured to use default timeout values when connecting to other DNS servers. These settings work well under most conditions when a dedicated Internet connection is available. For users with dial-on-demand Internet connections, the default values may need to be changed.
The settings can be changed by using a resource-editing utility such as ResEdit to modify certain resources (described below) in a copy of the MacDNS application. Alternatively, copies of these resources may be added to the MacDNS Preferences file, where they will override the default resources in the MacDNS application. This document assumes that you already know how to use ResEdit.
IMPORTANT It is usually not necessary to modify any of these settings. If you are not sure whether to change a setting, leave it alone.
TCP Listeners ('STR ' resource ID=360)
This value specifies the maximum number of simultaneous TCP connections that can be accepted. Generally, TCP connections are used only for zone transfers, so increasing this value does not help unless your secondary name servers are experiencing problems transferring all the zones you are serving. The default number is 5. If a value less than 5 or greater than 64 is specified in this resource, the default number will be used. Large values may require additional memory to be allocated to the application.
UDP Listeners ('STR ' resource ID=361)
This value specifies the maximum number of simultaneous UDP transactions that can be processed. Most DNS requests are serviced through UDP transactions. Since UDP transactions usually take less than a second, increasing this value does not help unless your server is receiving an extremely high volume of requests. The default number is 7. If a value less than 7 or greater than 64 is specified in this resource, the default number will be used. Large values may require additional memory to be allocated to the application.
Lookup timeout ('STR ' resource ID=362)
This value specifies the amount of time, in ticks, that MacDNS waits for a response from a parent server each time it attempts a lookup. A tick is a unit of time equivalent to 1/60 second. The default value is 120 ticks (that is, 2 seconds). If a value less than 30 ticks (0.5 seconds) or greater than 72000 (20 minutes) is specified, the default value will be used.
Lookup retries ('STR ' resource ID=363)
This value specifies the total number of attempts that MacDNS will make to contact a parent server. If the first attempt does not succeed within the timeout interval (specified above), additional attempts are made until the total number is reached. The default number is 3. If a value less than 1 is specified, the default value will be used. There is no upper limit on the number of retries.
Parent server poll interval ('STR ' resource ID=364)
This value specifies the interval, in seconds, between attempts to poll a parent server in order to measure its responsiveness. These measurements help MacDNS determine which parent server to contact first. The default interval is 60 seconds. If a value less than 20 seconds (but greater than 0) is specified, the default interval will be used. If 0 is specified, MacDNS will not measure parent server responsiveness.
Self-test interval ('STR ' resource ID=365)
This value specifies the interval, in seconds, between attempts to perform a UDP self-test. This test helps MacDNS determine whether it is actively responding to requests, or whether it needs to reset itself. The default interval is 60 seconds. If a value less than 10 seconds (but greater than 0) is specified, the default interval will be used. If 0 is specified, MacDNS will not measure its own responsiveness.
Changes to MacDNS
This section provides details about the changes in the 1.0.4 release of MacDNS.
• Some attributes of MacDNS that were formerly not configurable can now be changed using ResEdit. Specifically, these include the number of maximum concurrent UDP transactions and TCP connections allowed, the lookup timeout value and number of retries, and the polling intervals for measuring server responsiveness. (Refer to the previous section for more information.)
• Fixed a bug that could cause a crash if an illegal CNAME record (specifying the same DNS name for both the alias and canonical names) was encountered, either in parsing a response from a parent server or when importing a zone file.
• Fixed a bug that could cause a freeze or crash when closing the Host Information window for a cached host, if that host had at least one alias or mail exchanger and had expired from the cache.
• Some users encountered a situation where MacDNS received a packet sent from its own IP address at port 53. (This should never occur in normal usage, because MacDNS never issues queries from that port.) The reply to this bogus packet then kicked off an endless series of “Received packet from myself/Sent response to myself” transactions. To prevent this from occurring, MacDNS now explicitly ignores any incoming packets from its own IP address at port 53, since these are never legitimate.
• Fixed a problem where changes to the MacDNS Preferences file were not being flushed to disk immediately after the file was updated. If the server subsequently crashed or was forced to quit abnormally, the changes could be lost. In some instances, the file’s resource map could become corrupted.
• Fixed a problem when printing host lists. The printed area of a page was incorrectly clipped to the size of the window being printed.
• Fixed a bug that prevented a newly added permanent host entry from being found during an “in-addr.arpa” lookup if the cache previously contained a Negative entry matching the host’s IP address.
• It was still possible to double-click on a cached host entry and get a dialog that read, “This field only accepts numbers between 1 and 1000001.” This occurred if the TTL value for that entry had already expired (that is, had reached 0) but the entry had not yet been removed from the cache.
• To support localization of MacDNS, all log messages have been moved into 'STR#' resources.
