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Cisco IOS Network Management Configuration Guide, Release 12.4T
- Basic System Management
- System Monitoring and Logging
- Troubleshooting, Fault Management, and Logging
- Cisco IOS Scripting with Tcl
- Cisco Networking Services (CNS)
- Cisco Discovery Protocol (CDP)
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DistributedDirector
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End of Life of DistributedDirector
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DistributedDirector Enhancements for Cisco IOS Release 12.1(5)T
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DistributedDirector Configurable Cache
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DistributedDirector Cache Auto Refresh" in Distributed Director Configuration of 12.4 NM CG
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DistributedDirector Boomerang Support
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DistributedDirector MIB Support
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DNS Server Support for NS Records
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Configuring a DRP Server Agent
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- Embedded Event Manager (EEM)
- Embedded Menu Manager (EMM)
- Embedded Resource Manager (ERM)
- Embedded Syslog Manager (ESM)
- HTTP Services
- RMON Support
- SNMP Support
- SNMP MIBs
- TR-069 Agent
- VPN Device Manager for XSM
- Web Services Management Agent (WSMA)
- XML-PI
Table Of Contents
DistributedDirector Configurable Cache
Related Features and Technologies
Supported Standards, MIBs, and RFCs
Configuring the Size of the Cache
Configuring How Long the System Retains Sorting Information
Verifying DistributedDirector Cache Information
Configuring the Size of the Cache Example
Configuring How Long the System Retains Sorting Information Example
DistributedDirector Configurable Cache
Note
Effective with Cisco IOS Release 12.4(24)T, this feature is not available in Cisco IOS software.
Feature History
This document describes the DistributedDirector Configurable Cache feature in Cisco IOS Release 12.2(8)T. It includes the following sections:
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Feature Overview
DistributedDirector maintains an internal cache of entries that is dynamically configurable. This internal configurable cache consists of sorting events that occur on a per-client basis. Users can configure both the size of this internal cache and the amount of time for which the DistributedDirector system will retain per-client sorting information.
The DistributedDirector Configurable Cache feature allows users to configure their systems in order to limit the amount of memory that DistributedDirector uses for Domain Name System (DNS) caching. When a query that is a duplicate of a previous query comes from the client within the cache timeout period, the same response can be produced without the use of any Director Response Protocol (DRP) queries or sorting.
The DistributedDirector Cache Auto Refresh feature works in the background to continuously update all entries in the DistributedDirector cache. Once this background refresh feature is initiated, DistributedDirector periodically updates all expired cache entries. The DistributedDirector cache saves the latest answers to all past DNS queries received since cache auto refresh was initiated, and any repeat request is served directly from the cache when caching is enabled.
Benefits
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Related Features and Technologies
DistributedDirector Cache Auto Refresh
Related Documents
DistributedDirector Cache Auto Refresh, Cisco IOS Release 12.2(8)T feature module
Supported Platforms
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Determining Platform Support Through Cisco Feature Navigator
Cisco IOS software is packaged in feature sets that support specific platforms. To get updated information regarding platform support for this feature, access Cisco Feature Navigator. Cisco Feature Navigator dynamically updates the list of supported platforms as new platform support is added for the feature.
Cisco Feature Navigator is a web-based tool that enables you to quickly determine which Cisco IOS software images support a specific set of features and which features are supported in a specific Cisco IOS image. You can search by feature or release. Under the release section, you can compare releases side by side to display both the features unique to each software release and the features in common.
To access Feature Navigator, you must have an account on Cisco.com. If you have forgotten or lost your account information, send a blank e-mail to cco-locksmith@cisco.com. An automatic check will verify that your e-mail address is registered with Cisco.com. If the check is successful, account details with a new random password will be e-mailed to you. Qualified users can establish an account on Cisco.com by following the directions at http://www.cisco.com/register.
Cisco Feature Navigator is updated regularly when major Cisco IOS software releases and technology releases occur. For the most current information, go to the Cisco Feature Navigator home page at the following URL: http://www.cisco.com/go/fn.
Supported Standards, MIBs, and RFCs
Standards
No new standards are supported by this feature.
MIBs
No new MIBs are supported by this feature.
To obtain lists of supported MIBs by platform and Cisco IOS release, and to download MIB modules, go to the Cisco MIB website on Cisco.com at the following URL:
http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml
RFCs
No new RFCs are supported by this feature.
Prerequisites
The sorting cache must be enabled on DistributedDirector. To enable the sorting cache, use the ip director cache command.
Configuration Tasks
See the following sections for configuration tasks for this feature. Each task in the list is identified as either required or optional.
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Configuring the Size of the Cache
To configure the variable size of the DistributedDirector cache, use the following commands in global configuration mode:
Configuring How Long the System Retains Sorting Information
To configure how long the DistributedDirector system will retain per-client sorting information, use the following command in global configuration mode:
Verifying DistributedDirector Cache Information
To show DistributedDirector cache information, use the show ip director cache command.
Router# show ip director cacheDirector cache is onCache current size = 2 maximum size = 2000Cache time for sort cache entries:60 secsDirector sort cache hits = 8Entries:www.myserver.org:for client 172.17.2.78, used 3 times, valid for:00:00:42server 172.21.34.10, rank 0, priority 0random incomplete:0DRP route lookup external to AS incomplete:0administrative preference incomplete:0DRP route lookup internal to AS complete:40DRP distance to associated server incomplete:0portion incomplete:0Round-trip time from DRP to client incomplete:0DFP originated weight incomplete:0Route-map evaluation incomplete:0Boomerang evaluation incomplete:0server 172.21.34.10, rank 0, priority 0, bestrandom incomplete:0DRP route lookup external to AS incomplete:0administrative preference incomplete:0DRP route lookup internal to AS complete:30DRP distance to associated server incomplete:0portion incomplete:0Round-trip time from DRP to client incomplete:0DFP originated weight incomplete:0Route-map evaluation incomplete:0Boomerang evaluation incomplete:0www.boom1.com:for client 172.17.2.78, used 5 times, valid for:00:00:13server 172.21.34.10, rank 0, priority 0random incomplete:0DRP route lookup external to AS incomplete:0administrative preference incomplete:0DRP route lookup internal to AS complete:40DRP distance to associated server incomplete:0portion incomplete:0Round-trip time from DRP to client incomplete:0DFP originated weight incomplete:0Route-map evaluation incomplete:0Boomerang evaluation incomplete:0server 172.21.34.10, rank 0, priority 0, bestrandom incomplete:0DRP route lookup external to AS incomplete:0administrative preference incomplete:0DRP route lookup internal to AS complete:30DRP distance to associated server incomplete:0portion incomplete:0Round-trip time from DRP to client incomplete:0DFP originated weight incomplete:0Route-map evaluation incomplete:0Boomerang evaluation incomplete:0Configuration Examples
This section provides the following configuration examples:
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Configuring the Size of the Cache Example
The following example configures the maximum number of cache entries:
Router(config)# ip director cache size 1500Cache size shrinked to 1500Router# show running-configip host myhost 172.18.18.10 172.18.18.20 172.18.18.30...ip director host myhostip dns primary myhost soa myhost myhost@comno ip director drp synchronizedip director cache size 1500Configuring How Long the System Retains Sorting Information Example
The following example configures how long the DistributedDirector system will retain per-client sorting information:
Router(config)# ip director cache time 100Router# show running-configip host myhost 172.18.18.10 172.18.18.20 172.18.18.30...ip director host myhostip dns primary myhost soa myhost myhost@comno ip director drp synchronizedip director cache time 100Command Reference
The following new commands are pertinent to this feature. To see the command pages for these commands and other commands used with this feature, go to the Cisco IOS Master Commands List, Release 12.4, at http://www.cisco.com/univercd/cc/td/doc/product/software/ios124/124mindx/
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Any Internet Protocol (IP) addresses used in this document are not intended to be actual addresses. Any examples, command display output, and figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses in illustrative content is unintentional and coincidental.
© 2007 Cisco Systems, Inc. All rights reserved.
