DNS Caching

  • Thread starter Thread starter David Johnson
  • Start date Start date
D

David Johnson

How can the DNS cache for a caching only DNS server be monitored? How many
entries does it cache? How long? Are any of these attributes configurable?
 
David Johnson said:
How can the DNS cache for a caching only DNS server be monitored? How many
entries does it cache? How long? Are any of these attributes
Click to expand...
configurable?

It depends on the DNS server. Some cannot.

With Win2000+ you must turn on the "View\Advanced" to
see the cache -- that is probably what you wanted.

With BIND, you probably have to configure it to save the
cache or write a program extension for viewing it real time.
(Maybe there is one out there, but I do save my cache
occasionally.)
[/QUOTE]
 
DJ> How can the DNS cache for a caching only DNS server be monitored?

Using the DNS management console.

DJ> How many entries does it cache?

As many as it can.

DJ> How long?

For the TTL period or for 86400 seconds, whichever is the shorter.

DJ> Are any of these attributes configurable?

Yes.
 
In
Herb Martin said:
It depends on the DNS server. Some cannot.

With Win2000+ you must turn on the "View\Advanced" to
see the cache -- that is probably what you wanted.

With BIND, you probably have to configure it to save the
cache or write a program extension for viewing it real time.
(Maybe there is one out there, but I do save my cache
occasionally.)
Click to expand...

And just to add, as for the question of 'how long?', that depends on the
records's TTL.

--
Regards,
Ace

Please direct all replies to the newsgroup so all can benefit.
This posting is provided "AS-IS" with no warranties and confers no
rights.

Ace Fekay, MCSE 2000, MCSE+I, MCSA, MCT, MVP
Microsoft Windows MVP - Active Directory
 
You can also enum the cache using command line tool dnscmd.exe. dnscmd is
installed with the Support tools on the server cd.
 
In
Jonathan de Boyne Pollard said:
For the TTL period or for 86400 seconds, whichever is the shorter.


Yes.
Click to expand...
You can change the Maximum cache Time to Live with this registry value, you
may want a longer cache TTL or you may want a shorter TTL, setting the Value
to 0 effectively disables caching. Reasons why you may want to set the
MaxCacheTtl to 0 could be if you have a Caching only root that you are
forwarding to.
Enter this value in seconds.

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\DNS\Parameters

MaxCacheTtl

Value: MaxCacheTtl
Added: SP4 (April 1998)
Type: DWORD
Default: NoKey (Cache for up to one day, or 86400 seconds)
Function: Set maximum caching TTL.

198408 - Microsoft DNS Server Registry Parameters, Part 1 of 3:
http://support.microsoft.com/default.aspx?scid=198408
 
Back
Top