Index

Overview

A Rewalk is a type of Discovery, but unlike a typical Discovery a Rewalk does not discover any new devices. Rather the Rewalk identifies configuration changes on known devices (those that have been previously discovered), updating the Statseeker configuration to match. The ‘Daily Rewalk’ is a scheduled Rewalk which, by default, occurs daily at 11am server-time.

  • The Rewalk schedule can be modified to occur at a different time
  • Additional Rewalks can be scheduled
  • Discovery processes can also be scheduled

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Scheduling Rewalk and Discovery Processes

Scheduled Rewalk and Discovery run as cron jobs and can be managed from within the Admin Tool:

  • Select Administration Tool > Expert Tools > Crontab

There may be multiple entries in your Statseeker crontab and the Rewalk\Discovery processes can be identified by the process name nim-discover. The crontab syntax is:

Minute  Hour  Day-of-Month  Month  Day-of-Week  Process-to-be-run  verbose-flag  verbose-level  discovery-type-flag  redirect-output

The default Rewalk entry is:

0 11 * * * nim-discover -v 3 -r > $SSHOME/nim/etc/discover.log 2>&1

Additional entries can be added to the crontab to provide additional Rewalks or to schedule automated Discoveries. When adding additional jobs, or modifying existing jobs, restrict changes to the schedule and discovery-type-flag. The options for these values are:

Field Values
Minute 0-59
Hour 0-23
Day-of-Month 1-31
Month 1-12
Day-of-Week 0-7 (0 and 7 = Sunday)
discovery-type-flag
  • h – Discovery using the Hosts file
  • R – Discovery using enabled IP Address Range configurations
  • r – Rewalk
Note:

  • Schedule value options
    • Each can be replaced by * to indicate ‘all values’
    • Supports hyphen separated ranges e.g.8-11
    • Support comma separated lists e.g. 8,9,11,12
  • The nim-discover process will first check to see if another instance of nim-discover is already running. Only a single nim-discover can run at a time, so schedule multiple process according to their typical duration within your network.
Example:

Entries for an 11am daily rewalk and a 10pm daily discovery by IP Address Ranges.

0 11 * * * nim-discover -v 3 -r > $SSHOME/nim/etc/discover.log 2>&1

0 22 * * * nim-discover -v 3 -R > $SSHOME/nim/etc/discover.log 2>&1
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