|21. Service Name:- Dnscache|
|Executable Name:-svchost.exe -k NetworkService|
|Log On As:-NetworkService|
|Description:-The Domain Name System (DNS) client service resolves and caches DNS names. The DNS client service must be running on every computer that will perform DNS name resolution. The ability to resolve DNS names is crucial for locating domain controllers in Active Directory domains. The DNS client service is also critical for locating devices identified using DNS name resolution.
The DNS Client service running on Windows implements the following features:
If the DNS client service is stopped or disabled on your computer, you may not be able to locate the domain controllers of the Active Directory domains and will no longer be able to locate the devices identified using DNS names.
- System-wide caching
Resource records (RRs) from query responses are added to the client cache as applications query DNS servers. This information is then cached for a set Time to Live (TTL) and can be used again to answer subsequent queries.
- RFC-compliant negative caching support
In addition to caching positive query responses from DNS servers (which contain resource record information in the answered reply), the DNS Client service also caches negative query responses. A negative response results when a resource record for the queried name does not exist.Negative caching prevents the repeating of additional queries for names that do not exist, which can adversely affect client system performance. Any query information negatively cached is kept for a shorter period of time than is used for positive query responses; by default, no more than 5 minutes. This avoids continued negative caching of stale information if the records later become available.
- Avoidance of unresponsive DNS servers
The DNS Client service uses a server search list, ordered by preference. This list includes all preferred and alternate DNS servers configured for each of the active network connections on the system.
|Avaliable on OS:-Windows XP Home, Windows XP Professional; Windows Server 2003, Standard Edition; Windows Server 2003, Enterprise Edition; Windows Server 2003, Datacenter Edition and Windows Server 2003, Web Edition.|
|Installed through:-Default operating system installation|
|This service depends on the following system components:-TCP/IP Protocol Driver, IPSEC Driver
|The following system components depend on this service:- None|
|Port Numbers used:-TCP: 53|