Disabling Recursion

• Disable recursion to limit name resolution to a specific server, or as a failover for another DNS server
• Consequence: You will not be able to resolve names outside of your own zone
• Benefit: You will reduce the load on the DNS server

Deleting and Modifying Root Hints

• Delete root hints on servers that do not need to communicate with DNS servers that are authoritative for the root domain
• Update root hints when DNS servers that are authoritative for the root domain change
• Modify root hints if the root domain is internal

Optimizing DNS Server Response

To improve DNS server response time:
• Disable Local Subnet Prioritization
– Used when multiple records match a request
– Arranges the query response, so that the records closest to the client subnet are first
• Disable Round-robin rotation
– Used when multiple records match a request
– Rotates the order of responses for load balancing
• Install sufficient memory to cache all DNS zones in memory

Optimizing DNS Server Functionality

To optimize zone transfer:
• Modify depending on how often your DNS data changes
• Modify if more frequent updates are not required
• Use incremental zone transfers
To reduce network traffic, use caching-only servers:
• Use caching-only servers if you have a slow WAN link
• Configure caching-only servers to perform recursive queries

Optimizing Active Directory Integrated Zones

Select an appropriate application partition:
• ForestDNSZones replicates to all domains
• DomainDNSZones replicates within a domain
• _msdcs subdomain is in ForestDNSZones by default
To optimize AD integrated zones:
• Optimize Active Directory performance
• Use Active Directory sites
• Place logs and the Active Directory database on dedicated partitions

DNS Troubleshooting Tools

DNS troubleshooting tools are:
• NSLookup
• DNScmd
• DNSLint