---
title: "Operational Guidelines"
canonical: "https://docs.infoblox.com/space/dca9x/399082052/Operational%20Guidelines"
format: markdown
---
The specialized function of appliances that support DNS Cache Acceleration is to act as a high-speed DNS caching-only name server. The DNS Cache Acceleration appliances share the following characteristics:

- The DNS Cache Acceleration appliances support the following:
  - Up to six DNS views
  - Forward zones and stub zones, but not authoritative zones
  - Certain Finisar Copper and Fiber SFP modules
  - Anycast for BGP v6 and OSPF v3
  - DNS Anycast and IPv6 Anycast
  - Up to 10,000 entries for each ACL (Access Control List)
  - Only the cyclic ordering for A records over the IPv4 transport
- The LAN1, LAN2, MGMT and HA interfaces of DNS Cache Acceleration appliances support IPv4 and IPv6 transports and DNS services over IPv4 and IPv6 networks.
- The DNS Cache Acceleration appliances support the following IPv6 functions and applications:
  - DNS over IPv6 LAN1, LAN2, MGMT, and HA interfaces
  - IP6 addresses on a loopback interface
  - CLI (SSH) access over IPv6
  - GUI access over IPv6
  - PAPI access over IPv6
  - Sending SNMP traps over IPv6
  - SNMP query over IPv6
  - Sending messages to an external syslog server over IPv6
  - Email relay over IPv6
  - IPv6 static routes
- When a NIOS appliance or the host restarts, you might continue to receive responses for cached queries from the DNS cache accelerator. Queries that are not cached will not be answered.
- If query logging is enabled, only DNS queries will be logged.
- The DNS Cache Acceleration appliances do not support the following:
  - DHCP and IPAM functions
  - Zone transfers or dynamic DNS updates

In cache-accelerated mode, the DNS Cache Acceleration appliances have the following characteristics :

- They support DNS queries over IPv4 and IPv6 transports only for the following record types: A, AAAA, MX, PTR, and CNAME.
- When the DNS service restarts due to changes in the DNS configuration, all DNS caches are cleared.
- Appliances with cached acceleration do not support monitoring of DNS packets. They support DNS monitoring alerts and IP rate limiting.

The table below lists the features that are supported or not supported for the DNS Cache Acceleration feature on an appliance that supports DNS Cache Acceleration:

*Features on the DNS Cache Acceleration platforms*

| **Features** | **Supported / Not Supported - Software-Based appliances** |
| --- | --- |
| Tiered licensing | Supported  
Note that only IB-4015 and TE-4126 support tiered licensing. |
| RPZ | Supported  
For IB-FLEX appliances, only when you configure RPZ zones with DCA-enabled-flex-member, maximum cache lifetime is set to 300 seconds. |
| Caching (A, AAAA, MX, CNAME, PTR) | Supported |
| Caching of Type 64 and 65 resource records | Supported from NIOS 9.0.2 onwards |
| Resource records of type 64 and 65 (HTTPS and SVCB) | Supported from NIOS 9.0.2 onwards |
| Do not cache: EDNS, TCP, Any, TSIG | Supported |
| Caching over additional interfaces (v4, v6) | Supported |
| Dump Acceleration Cache (CLI, GUI, PAPI) | Supported |
| Clear Acceleration Cache (CLI, GUI, PAPI) | Supported |
| Cache pre-fetch and cache refresh | Supported |
| ACLs (Allow-queries/Responses, Match-Clients/Destination, Blackhole) | Supported |
| AAAA Filtering (Bypassed but support configuring) | Supported |
| Fixed RRSET ordering | Supported |
| DNS64 | Supported |
| DNS monitoring feature (netmon) | Supported |
| DNS Query logging (BIND only) | Supported |
| DNS Views | Supported |
| Forward/Stub zones | Supported |
| DNS cache acceleration related restrictions for configuration. | Supported |
| Reporting | Supported, see *[Supported Reports for DNS Cache Acceleration Appliances](https://infoblox-docs.atlassian.net/wiki/spaces/dca9x/pages/399802596)*. |
| VLAN | Supported |
| DSCP | Supported<br>DSCP is not supported when packets are processed by the DNS Cache Acceleration feature in software-based DNS cache acceleration appliances: IB-22*x*5, IB-V22x5, IB-40*x*5, IB-V40x5, TE-2326, TE-4126, IB-V2326, IB-V4126 |
| Sort list | Supported |
| Anycast (OSPF and BGP) | Supported |
| BFD (Bidirectional Forwarding Detection) | Supported |
| HA Support | Supported |
| NIC Bonding | Supported |
| Multiple-Interfaces on same subnet | Not supported |
| IP Rate-limit and Response logging | Not supported |
| EDNS Client Subnet support | Not supported |
| NXDOMAIN redirection | Supported |
| DNSSEC (Bypassed but support configuring) | Supported |
| Debug enhancements | Supported |
| SNMP Support for DCA service related traps | Supported |
| SNMP stats support for DNS QPS and CHR | Supported |
| NX Mitigation | Not supported |
| NetFilter (Tracking tables) | Supported |
| Traffic-capture (All modes) | Supported |
| No flush-mode support for DNS cache acceleration cache | Supported |
| Per-interface UDP DNS cache acceleration response counters | Supported |
| CLI commands | You can use the  commands `set dns-accel` and `show dns-accel`  to view and set the DNS Cache Acceleration. For more information, see *[DNS Cache Acceleration CLI Commands](https://infoblox-docs.atlassian.net/wiki/spaces/dca9x/pages/399474987)*. |
| DNS Query rewrite (Bypassed but supports configuring) | Not supported |
| Threat Protection | Supported |