IBM Cloud DNS services is happy to announce the addition of key features for its custom resolver product, including two new, more scalable tiers—Advanced and Premier—which enable enterprise-scale and new capabilities within the service.  
 
The Domain Name System (DNS) plays a critical role in the smooth operation of the internet, acting as the "phone book" of the web by translating human-friendly domain names into IP addresses. Within the DNS, zone transfers are essential for maintaining consistency and synchronization among authoritative name servers. Two primary methods for DNS zone transfers are Incremental Zone Transfer (IXFR) and Full Zone Transfer (AXFR). In this blog, we’ll focus on IXFR, exploring its customer use cases, benefits, and the concept of DNS views. 

DNS Incremental Zone Transfer (IXFR) 

IXFR is a more efficient way to update zone information compared to AXFR. Instead of transferring the entire zone file, IXFR transfers only the changes (deltas) made since the last update. This reduces the amount of data transferred, saving bandwidth and processing time. 

• Features
  • Version Comparison: The secondary DNS server's zone version is compared to the primary DNS server's version using the serial number in the Start of Authority (SOA) record.
  • Update Transfer: If the primary server has a newer version, it sends only the changes to the secondary server. If the versions match, no transfer occurs.
  • Efficiency: IXFR reduces the load on network resources by transferring only the necessary updates. 

• Use Cases
  • Large Enterprises: These organizations manage numerous DNS zones with frequent updates. IXFR helps minimize both the time and bandwidth needed for zone transfers.
  • Dynamic Environments: Online services with dynamic DNS updates, such as IoT devices or constantly changing web services, benefit from IXFR's efficiency in propagating frequent changes. 

• Benefits
  • Business Continuity (BC) /Disaster recovery (DR): IXFR enables the backup of production zones to the cloud (and vice versa), enabling a hybrid DNS solution with maximum resiliency.
  • Efficiency: IXFR greatly reduces the amount of data transferred, which is beneficial for large DNS zones.
  • Scalability: By only transferring necessary updates, IXFR supports scalable DNS infrastructures that can grow with your business.
  • Reduced Latency: Faster synchronization of DNS records leads to lower latency, ensuring quicker access for end-users accessing updated DNS entries.
  • Lower Costs: Efficient data transfer translates to lower operational costs, especially for enterprises with vast and dynamic DNS setups. 

DNS Views 
DNS views, also known as split DNS, allow administrators to present different DNS information based on the source of the query. This is particularly useful for providing different internal and external DNS responses or for segmenting DNS data across various network segments

• Features
  • Multiple Views: Administrators can configure DNS views based on client IP addresses, allowing different sets of DNS records to be served.
  • Internal and External Views: Typically, internal views return private IP addresses for internal network requests, while external views serve public IP addresses for external queries.
  • Segmentation: DNS views can also segment DNS data for different clients, improving both performance and security.  

• Use Cases
  • Enterprises with Internal Networks: Large enterprises can leverage DNS views to provide different DNS responses for internal and external network queries, ensuring security and customized responses.
  • Segmented Data: ISPs and managed DNS providers can segment DNS data for different clients, improving performance and security.
  • Security and Compliance: Organizations with strict compliance requirements can use DNS views to restrict access to sensitive DNS information, limiting visibility to specific internal segments.  

• Benefits
  • Security: Control visibility of private DNS data to internal systems and users.
  • Performance: Optimize responses for external and internal users based on their requesting network.
  • Optimized Zone Management: Enable administrators to control DNS zones and records, ensuring compliance and streamlined service