DNS caching service (dnscache)
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| This article applies to the following ZCS versions. |
DNS caching service (dnscache)
Starting with Zimbra Collaboration 8.5 and later, there is now a DNS caching service available for installation. It is specifically targeted for MTA nodes, and could be perfect for Single-Server Installations. Three of our supported features are raly heavily on DNS lookups:
- DKIM verification
- SpamAssassin Scoring
- Postfix RBLs for spam blocking
However, remote sites that provide the SpamAssassin scoring and Postfix RBLs do *not* like heavy DNS traffic overloading their servers for some reason. Prolonged over-use of their DNS systems will in fact get your MTAs blacklisted from using those services, severely reducing the effectiveness of said services.
How it works
How to enable it
To ensure our clients do not have their MTAs blacklisted the DNS caching package is now part of ZCS. General setup:
Answer [Y] to install zimbra-dnscache When prompted, list the IP(s) of the sites local DNS servers
The installer will automatically reconfigure the DNS cache as the primary resolver for the OS.
NOTE: SHOULD NOT BE INSTALLED ON SYSTEMS THAT ALREADY HAVE BIND OR OTHER DNS SERVICES INSTALLED. Instead, the client should configure such servers to also act as a DNS cache.
Testing the DNS caching service (dnscache)
Identified Support Issues
Reference: https://bugzilla.zimbra.com/show_bug.cgi?id=83670
