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Contents 1 Introduction 1.1 Domain 1.2 IfAlias 2 Usage 3 The collectd-configuration.xml file 4 FAQ 5 Version History/Availability

Introduction

This article explains how to configure Snmp data collection to store interface data by the optional domain/ifAlias method.This method provides advantages for managing data storage in an environment of distributed management and frequent adds, moves, and changes. It is assumed that the reader is already familiar with basic data collection configuration. If not, see Data_Collection_Configuration_How-To. For a more detailed discussion of the use case for domain/ifAlias data storage see Data_Storage_and_Display_Options. This feature is available beginning with release 1.3.2.

Domain

The term domain as used here describes any logical grouping of network switches and/or routers based on functional or administrative considerations. Examples would be 1) One or more switches providing network connectivity to a group of servers at a server farm. 2) one or more routers connecting a group of remote sites to a central facility.

IfAlias

IfAlias refers to an administrator-assigned name for an interface on a network device such as a switch or router. The ifAlias for an interface may be set via SNMP or through a management interface on the network device. For the example domains listed above, ifAliases might be 1) the names of the servers at the server farm, or 2) the names of the remote sites or their circuit IDs. See ifAlias for more information.

Usage

1. The OpenNMS administrator chooses to enable this optional data storage feature for a group (domain) of network nodes. Members of the domain may be chosen based on departmental administrative boundaries, or any other rationale that provides a logical grouping of devices. A domain may contain a single device or many.
2. The OpenNMS administrator configures a separate data collection package for each domain. Package options provide additional flexibility when a combination of storage methods is desired for the nodes covered by a package.
3. The network administrator configures descriptive names (ifAliases) for the active ports on each switch or router in the network administrator's domain. These should be unique within the domain.
4. OpenNMS users view data stored by domain/ifAlias from Home > Reports > Resource Graphs by selecting one of two new viewing choices Standard Domain Performance Reports and Custom Domain Performance Reports. Users may also view data from Home > Reports > KSC Reports by selecting the new choice Domain Reports or by incorporating individual graphs into KSC Performance Reports.
5. OpenNMS users may search for nodes on the OpenNMS system with interfaces having an ifAlias matching a string of characters using a new choice on the search page, ifAlias containing. This is a partial string match analogous to the Name containing search.
6. When the network administrator moves a device such as a server to a new physical port, he/she deletes the descriptive name (ifAlias) from the old port's configuration and adds it to the new port's configuration. OpenNMS continues to store interface data associated with the server in the same rrd file used before the move.
7. OpenNMS users view traffic data to/from the server moved in the previous item using one of the new viewing options and see a continuous graph of interface data covering the time periods before and after the move.

The collectd-configuration.xml file

Below is an example from collectd-configuration.xml used for domain/ifAlias storage. Each new option will be explained below.

<package name="example2">
  <filter>IPADDR IPLIKE *.*.*.*</filter>   
  <specific>1.1.1.1</specific>
  <include-range begin="1.1.1.2" end="1.1.1.3"/>
  <include-url>file:/etc/opennms/include</include-url>
  <storeByIfAlias>true</storeByIfAlias>
  <storeByNodeID>normal</storeByNodeID>
  <ifAliasDomain>mydomain</ifAliasDomain>
  <storFlagOverride>true</storFlagOverride>
  <ifAliasComment>#</ifAliasComment>
                
  <service name="SNMP" interval="300000" user-defined="false" status="on">
    <parameter key="collection" value="default"/>
    <parameter key="port" value="161"/>
    <parameter key="retry" value="3"/>
    <parameter key="timeout" value="3000"/>
  </service>
</package>

storeByIfAlias 

This is the main configuration parameter for this feature. If it is absent or false, all the following options are ignored, and data storage proceeds in the regular manner as before. Allowable values are true (yes,on) or false (no, off). Default is false.

storeByNodeID 

Determines if data will be stored by nodeId/interface. Allowable values are true (yes, on), normal, or false (no, off). True means data will be stored by nodeId/interface if data is being stored by domain/ifAlias OR if the snmpStorageFlag indicates it should be stored . False means data will not be stored by nodeId/interface. Normal means data will be stored by nodeId/interface according to the setting of the snmpStorageFlag. Default is normal.

ifAliasDomain 

This text string specifies the name for the domain. If it is absent, the name defaults to the package name.

storFlagOverride 

If true, data will be stored by domain/ifAlias regardless of the snmpStorageFlag setting. If false, data will only be stored by domain/ifAlias if an ifAlias exists for an interface AND the snmpStorageFlag would normally permit data from this node and interface to be stored. Allowable values are true (yes, on) and false (no, off). Default value is false.

ifAliasComment 

An optional comment character that can be used by network administrators when assigning ifAliases to interfaces. The comment character and all following characters will be ignored when creating file names for storage by domain/ifAlias. Any white space immediately preceding the comment character will also be ignored. The comment character can be used to add information to an ifAlias that may change with a move, such as a wiring jack number, without affecting the file name used for storage. An ifAlias that begins with a comment character is treated as if the interface has no ifAlias. Default is no character.

 See also: Domain_ifAlias_storage_matrix
 See also: IfAlias.

FAQ

A FAQ can be found at Domain-IfAlias_Data_Storage_FAQ

Version History/Availability

• This feature was added in version 1.3.2