DNS Client
23 July 2000 by Snakefoot | Comment » | Trackback OffDescription:
The DNS Client acts like a local DNS server, and is used whenever an application requires to resolve a Domain Name System(DNS) name.If an application wants to connect to www.google.com, then it requests the DNS client for it to convert it to an IP address. If the DNS client doesn't recognize the domain it passes the request to the network DNS Server (Port 53), but caches the reply for later use by the same or other applications and thus increases the speed of future DNS lookups and causes less load on the network DNS Server.
When using WinXP to logon to a domain one should register the domain server's IP as the primary DNS Server. If this is not done the login to the domain will be very slow.
When using Win2k/WinXP to logon to a WinNT4 domain one should enable Netbios over TCP/IP for the Internet Protocol in network properties on Win2k/WinXP as the WinNT4 domain doesn't use DNS.
Note if using a large HOSTS file to ban ads, then it will lead to slow performance when having the DNS Client enabled. To avoid the slowdown, then one either has to disable the DNS Client or avoid using a large HOSTS file.
Note in Windows XP this service keeps the same UDP connection open to make all DNS requests. In Windows 2000 the service opens/closes a UDP connection for each request. To make XP behave like Windows 2000 use this DWORD registry key:
Note if having disabled this service, and then try to repair a network connection, one will get the following error message:[HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services \Dnscache \Parameters]
MaxCachedSockets = 0
Related Configure how long to cache negative DNS repliesThe following steps of the repair operation failed: Purging the DNS Resolver Cache. Please contact your network administrator or ISP.
More Info MS KB Q913631
Related Microsoft TCP/IP Version 6 (IPv6) can cause slow DNS
Related Configure the host name resolution order
Related Use HOSTS file to ban ads and speedup DNS lookups
More Info MS KB Q286834
More Info MS KB Q264539
More Info MS KB Q268674
More Info MS KB Q245437
More Info MS KB Q246804
More Info MS KB Q294832
More Info MS KB Q320760
Recommended State:
- Automatic, to minimize network traffic for the cost of memory.
- Disabled, if not wanting to have DNS caching and want every application to do their own DNS lookup.
Default State:
- Automatic
Process Name:
- Win2k: services.exe (Dnscache)
- WinXP/Win2k3/Vista: svchost.exe -k NetworkService (Dnscache)
Supports:
- None
Depends:
- None
Tags:
Category:
Updated: 23 September 2007
Comment by Guest - 2 August 2003 @ 16:38 Reply
It may be useful for your users to know that the XP DNS service is not in fact necessary to resolve dns lookups while using the internet. Disabling it simply removes XP’s dns caching. Any machine less than a year old won’t notice a speed difference but will gain some memory and cpu cycles.
It is disabled on my system even now and I was able to dns to your site just fine.
Thanks for an excellent service.