• Pradip
• 14 Nov, 2025
• 0 Comments
• 2 Mins Read

Fixing INS-40719: SCAN IP Already Assigned

Fixing INS-40719: SCAN IP Already Assigned – Oracle Grid Infrastructure Installation Error

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When installing Oracle Grid Infrastructure 19c for RAC, one of the most common issues beginners face is the SCAN configuration error:

INS-40719: IP address configured for Single Client Access Name (SCAN) is already assigned to another system.

This error stops the installation unless you fix the SCAN IPs.

In this blog, we explain why it happens, how to solve it, and how to properly configure your /etc/hosts file for RAC.

Why This Error Happens (INS-40719)

Oracle requires 3 dedicated SCAN IPs for the RAC cluster. These IPs must be:

• Not assigned to any machine

• Not pingable

• Reserved exclusively for SCAN

If you enter SCAN IPs that are already used by VirtualBox, a VM, or any other device, the installer immediately throws the error.

Solution — Use New Unused SCAN IPs

You must select three fresh, unused IP addresses from your network range.

Since your network is:
192.168.56.x

Run ping on 3 IPs that are not in use:

If the result shows:

or

➡️ These IPs are free.
➡️ Use these three as your SCAN IPs.

What Next? Update /etc/hosts File

Once you confirm free IPs, update the /etc/hosts file on both nodes.

Below is the complete recommended hosts file for a 2-node RAC setup:

Full /etc/hosts File for RAC (Working Example)

Replace IPs with your real ones.
This is based on your environment where:

• node1: 192.168.56.91

• node2: 192.168.56.92

• SCAN IPs: 192.168.56.101–103

• Public, Private, VIP included

127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6

# Public
192.168.56.71 node1.learnomate.org node1
192.168.56.72 node2.learnomate.org node2

# Private
192.168.10.1 node1-priv.learnomate.org node1-priv
192.168.10.2 node2-priv.learnomate.org node2-priv

# Virtual
192.168.56.81 node1-vip.learnomate.org node1-vip
192.168.56.82 node2-vip.learnomate.org node2-vip

# SCAN (use free IPs)
192.168.56.101 node-scan.learnomate.org node-scan
192.168.56.102 node-scan.learnomate.org node-scan
192.168.56.103 node-scan.learnomate.org node-scan

After Updating Hosts File

Restart the installer and proceed. The error will be resolved because the installer now sees:

✔ Unique SCAN name
✔ 3 free SCAN IPs
✔ Correct hostname mapping

Final Notes

• SCAN IPs must not be used by any machine.

• SCAN works as a round-robin DNS entry; that’s why all 3 resolve to the same name.

• Never assign SCAN IPs to any interface manually.

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