F5SPKDnscache Reference¶

This overview discusses the F5SPKDnscache CR. For the full list of CRs, refer to the SPK CRs overview. The F5SPKDnscache Custom Resource (CR) configuration parameters. The F5SPKDnscache is referenced by the F5SPKEgress CR and must be created first. Each heading below represents the top-level parameter element. For example, to set the DNS Cache name, use spec.name.

spec¶

Parameter	Description
`name`	The name for this DNS cache instance. The name will be referenced in the F5SPKDns CR.
`cacheType`	The type for this DNS cache: netResolver or transparent.
`answerDefaultZones`	Whether to answer queries for default zones: localhost, reverse 127.0.0.1 and ::1 or AS112 zones. The default is false.
`description`	The description for this cache instance.
`forwardZones.forwardZone`	The Fully Qualified Domain Name for a Forward Zone.
`forwardZones.nameServers`	An array of Name Servers for a Forward Zone.
`forwardZones.nameServers.ipAddress`	The IP address for a Name Server, either v4 or v6.
`forwardZones.nameServers.port`	Port for a Name Server.
`localZones.name`	The Fully Qualified Domain Name for a localZone.
`localZones.zoneType`	The zoneType for this localZone: deny, refuse, static, transparent (default), typeTransparent or redirect.
`localZones.records`	Array of records for this localZone.
`localZones.records.items`	Fully specified resource record in the format name ttl class type data.
`msgCacheSize`	Number of bytes allocated for the message cache. The default is 1048576.
`nameserverCacheCount`	Maximum number of DNS Name Servers to cache. The default is 166536.
`nameserverTTL`	Time to live, in seconds, for DNS Name Servers in the cache. The default is 900.
`negCacheSize`	Number of bytes allocated for the negative cache. The default is 1048576.
`randomQueryNameCase`	Enables resolver to randomize the case of query names: true (default) or false.
`rrsetCacheSize`	Number of bytes allocated for the resource record set cache. The default is 10485760.
`rrsetRotate`	Specifies which resource record set rotation method should be used on cache responses: none (default) or query-id.
`useIpv4`	Enables the resolver to issue IPv4 queries: true (default) or false.
`useIpv6`	Enables the resolver to issue IPv6 queries: true (default) or false.
`useTcp`	Enables the resolver to issue TCP queries: true (default) or false.
`useUdp`	Enables the resolver to issue UDP queries: true (default) or false.

cacheType setting¶

By caching DNS responses and answering queries from the cache, the BIG-IP system is able to immediately respond to subsequent client requests for the same resource. This enhances DNS performance in two significant ways. First, answering a DNS query from the cache is faster and has a very short latency, because the sooner a client gets a DNS response, the faster the client can access the Internet resource. Secondly, caching DNS responses reduces the number of queries that have to be resolved. The BIG-IP system uses the cache to resolve the same query from multiple clients handling many more queries per second than a typical DNS resolver.

Currently, only the Transparent and Net Resolver cache types are supported.

localZones¶

Applicable only to the Transparent and Resolver caches, a local zone contains resource records that a DNS cache uses to resolve matching DNS queries with authoritative DNS responses. The zoneType attribute of the local zone determines how the cache handles a DNS query that does not match the local zone.

Parameter	Description
`deny`	For a non-matching query, the cache drops the DNS query. This is an example of a response to a non-matching query: DNS request timed out.
`redirect`	For a non-matching query, when the query is for a subdomain of the local zone, the cache returns the same response that it would for the local zone. For example, if you add the local zone siterequest.com, the cache returns the same response to queries for wiki.siterequest.com. and download.wiki.siterequest.com. This is an example of a response to a non-matching query: NOERROR rcode returned and example.com. NOT resolved as expected.
`refuse`	For a non-matching query, the cache returns a REFUSED message in the DNS response. This is an example of a response to a non-matching query: REFUSED rcode returned and example.com. NOT resolved as expected.
`static`	For a non-matching query, the cache returns a NoData or NXDOMAIN in the DNS response, which also includes the SOA record if the local zone contains one. This is an example of a response to a non-matching query: NOERROR rcode returned and example.com. NOT resolved as expected.
`transparent`	Transparent is the default value. For a non-matching query, the cache performs a pass-through or iterative resolution of the DNS query. If the query matches, but no resource records are available, the cache returns a response with a NoData message. This is an example of a response to a non-matching query: NOERROR rcode returned and example.com. NOT resolved as expected.
`typeTransparent`	For a non-matching query, or a query for a matching domain name, but with a request for a record of a different type, the cache performs a pass-through or iterative resolution of the DNS query; however, if the query matches, but no resource records are available, the cache does not return a response with a NoData message. This is an example of a response to a non-matching query: DNS request resolved to example.com. as expected.