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How IRE Identifies an Existing CI

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In this lesson, you will learn:

  • How IRE looks for a matching CI
  • What happens with one match, many, or none
  • Why clean data matters for matching

🔁 Quick look back: Last time: Assessing the Existing CMDB Before Discovery. You learned how to assess the existing CMDB before the first scan.

1 The Problem: Discovery Must Recognise Servers It Already Knows

When Discovery finds snwr-mail-01, the CMDB already has a record for it. Discovery must:

  • Recognise that it’s the same server.
  • Update that record, not add a new one.

🎯 The problem: Discovery must recognise servers the CMDB already knows.

👉 The fix: IRE compares the data with identification rules to find the existing CI.

Flow: payload, try rule 1, try rule 2, match found, update.
Figure 1. How IRE matches snwr-mail-01.

2 How matching works

  1. Discovery sends a payload with the device’s details.
  2. IRE picks the identification rule for the class.
  3. It tries the rule’s entries in order, such as serial number, then name.
  4. It stops at the first entry that finds a match.
Result What IRE does
One match Updates that CI.
No match Creates a new CI.
More than one match Flags a duplicate. It doesn’t guess.

3 Why clean data matters

If the old CI’s name is ‘SNWR-MAIL-01.snwr.local’ and Discovery reports ‘snwr-mail-01’, they may not match. Then IRE creates a new CI.

💡 Good to know: Check how Discovery will format names, and clean old names to match before scanning.

4 Project Clear View: How We Implemented It

📍 Situation: SNWR’s CIs have no serial numbers, so IRE will match on names.

🧭 Decision: Check that old names will match what Discovery reports.

🛠️ Steps we took:

  1. Compared spreadsheet names with the real hostnames on 10 servers.
  2. Found 7 names with a domain suffix or different case.
  3. Agreed with Hana to clean those names before the pilot.
  4. Noted that after the first scan, serial numbers will help matching.

✅ What we verified:

  • Cleaned names match real hostnames on the test servers.
  • Hana owns the name cleanup task.

📁 Evidence: A name cleanup task in the CMDB readiness report.

5 Quick recap

  • IRE uses identification rules to find a matching CI.
  • It tries entries in order and stops at the first match.
  • No match creates a new CI. Many matches flag a duplicate.
  • Clean names before scanning if serial numbers are missing.

6 Check yourself

Think of your answer first. Then tap to check.

1 What does IRE do when it finds exactly one match? Show answer

It updates that CI.

2 What does IRE do when it finds two matches? Show answer

It flags a duplicate instead of guessing.

3 Why did SNWR clean names before the pilot? Show answer

There were no serial numbers, so matching relied on names that had to match the real hostnames.

Nice work! You know how IRE recognises a known CI. 🎉
Next up: Identification Rules

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