Wednesday, August 26, 2026

Linux - WebLogic IP Address Change Procedure

 




1. Purpose

This document provides a standard procedure for changing the Linux WebLogic Server IP address when the underlying server IP address changes.

The procedure is designed to identify and update WebLogic configuration references to the old IP address while minimizing configuration impact and providing a clear rollback process.

2. Scope

This procedure applies to WebLogic domains where the server's IP address is changing.

It covers:

  • WebLogic Admin Server

  • WebLogic Managed Servers

  • Node Manager

  • startup.properties

  • WebLogic domain configuration

  • Operating system host configuration

  • Other configuration files containing the old server IP

The actual WebLogic installation and domain paths may vary by environment.

3. Prerequisites

Before starting the IP address change:

  1. Confirm the current/old IP address.

  2. Confirm the new IP address.

  3. Confirm the new IP is assigned to the server.

  4. Verify network connectivity using the new IP.

  5. Obtain appropriate OS and WebLogic administrative access.

  6. Schedule an appropriate maintenance window.

  7. Confirm all WebLogic services that will be impacted.

  8. Take a backup of the WebLogic domain configuration.

4. Verify Current Server Configuration

Check the current IP address:

hostname -I

or:

ip addr

Verify hostname resolution:

hostname
hostname -f

Check /etc/hosts if applicable:

cat /etc/hosts

Verify connectivity to the new IP or required network endpoints before proceeding.

5. Stop WebLogic Services

Stop the WebLogic Admin Server, Managed Servers, and Node Manager as required by the environment's standard shutdown procedure.

Verify that WebLogic processes have stopped:

ps -ef | grep -i weblogic | grep -v grep

Do not proceed with configuration changes while active WebLogic processes are using the configuration being modified.

6. Backup WebLogic Configuration

Identify the WebLogic domain directory.

Example:

export DOMAIN_HOME=/path/to/weblogic/domain

Create a backup before making any changes:

tar -czvf ${DOMAIN_HOME}_backup_$(date +%Y%m%d_%H%M%S).tar.gz "$DOMAIN_HOME"

Verify the backup:

ls -lh ${DOMAIN_HOME}_backup_*.tar.gz

Keep the backup until the IP change has been successfully validated.

7. Identify References to the Old IP

Search the WebLogic domain for references to the old IP address:

grep -RIn "OLD_IP_ADDRESS" "$DOMAIN_HOME" 2>/dev/null

Replace OLD_IP_ADDRESS with the actual old IP.

Also search specifically for startup.properties:

find "$DOMAIN_HOME/servers" \
-type f \
-name "startup.properties" \
-exec grep -Hn "OLD_IP_ADDRESS" {} \;

This identifies only the startup.properties files that contain the old IP.

8. Update startup.properties

startup.properties files may contain server-specific configuration, including IP addresses.

Before modifying these files:

  • Confirm the old IP belongs to the server being changed.

  • Do not modify files that do not contain the old IP.

  • Create a backup of each file being modified.

A generic replacement command is:

find "$DOMAIN_HOME/servers" \
-type f \
-name "startup.properties" \
-exec grep -l "OLD_IP_ADDRESS" {} \; \
-exec cp {} {}.bak \; \
-exec sed -i 's/OLD_IP_ADDRESS/NEW_IP_ADDRESS/g' {} \;

Where:

OLD_IP_ADDRESS = Current server IP
NEW_IP_ADDRESS = New server IP

Important

The command above modifies a startup.properties file only when the old IP is found.

Files that do not contain the old IP are not modified.

9. Review Other WebLogic Configuration

The IP address may be referenced in locations other than startup.properties.

Search the entire WebLogic domain:

grep -RIn "OLD_IP_ADDRESS" "$DOMAIN_HOME" 2>/dev/null

Review any references found in areas such as:

  • config.xml

  • startup.properties

  • Node Manager configuration

  • WebLogic startup scripts

  • Admin Server configuration

  • Managed Server configuration

  • Machine configuration

  • JDBC configuration

  • JMS configuration

  • SSL configuration

  • Listen Address configuration

  • Application configuration

  • Custom scripts

Do not automatically replace every occurrence. Review each reference to determine whether the IP should actually change.

10. Check Node Manager

Review the Node Manager configuration if Node Manager uses the server IP.

Typical location:

$DOMAIN_HOME/nodemanager/nodemanager.properties

Search for the old IP:

grep -n "OLD_IP_ADDRESS" \
"$DOMAIN_HOME/nodemanager/nodemanager.properties"

If the old IP is configured and should be replaced, update it with the new IP.

11. Check Operating System Configuration

Review /etc/hosts:

grep -n "OLD_IP_ADDRESS" /etc/hosts

If the old IP is configured for the WebLogic server, update it as required.

Verify hostname resolution:

getent hosts $(hostname)

12. Check External Dependencies

The WebLogic server IP may also be referenced outside the WebLogic domain.

Review the following where applicable:

  • DNS

  • Load Balancers

  • Reverse Proxies

  • Firewalls

  • Network ACLs

  • Monitoring systems

  • Backup systems

  • Security tools

  • Application integrations

  • Database connectivity

  • SSO integrations

  • API integrations

  • External systems

  • Infrastructure automation

  • Server Manager configuration

Coordinate with the appropriate infrastructure or application teams when these components are managed outside the WebLogic team.

13. Verify Configuration Changes

After making the changes, search for the old IP again:

grep -RIn "OLD_IP_ADDRESS" "$DOMAIN_HOME" 2>/dev/null

Review any remaining references.

Then verify the new IP:

grep -RIn "NEW_IP_ADDRESS" "$DOMAIN_HOME" 2>/dev/null

Confirm that the new IP appears only where expected.

14. Start WebLogic

Start the WebLogic environment using the standard startup procedure.

Verify WebLogic processes:

ps -ef | grep -i weblogic | grep -v grep

Confirm:

  • Admin Server is running.

  • Managed Servers are running.

  • Node Manager is running.

  • Applications are accessible.

15. Validate WebLogic

Review WebLogic logs after startup.

For example:

find "$DOMAIN_HOME/servers" -type f -name "*.log" -mmin -30

Search for common startup and connectivity errors:

grep -RInE "ERROR|Exception|Connection refused|UnknownHost|BEA-" \
"$DOMAIN_HOME/servers" 2>/dev/null

Validate application connectivity and any integrations dependent on the WebLogic server.

16. Post-Change Validation

Complete the following checks:

  • New server IP is configured correctly.

  • Network connectivity verified.

  • WebLogic domain backup completed.

  • Old IP references identified.

  • Required startup.properties files updated.

  • Only files containing the old IP were modified.

  • Node Manager configuration reviewed.

  • /etc/hosts reviewed.

  • WebLogic configuration reviewed.

  • DNS/load balancer configuration validated.

  • Admin Server started successfully.

  • Managed Servers started successfully.

  • Node Manager validated.

  • Application connectivity validated.

  • WebLogic logs reviewed.

  • External integrations validated.

17. Rollback Procedure

If WebLogic or an application does not function correctly after the IP change:

  1. Stop the affected WebLogic services.

  2. Identify the configuration changes made.

  3. Restore the affected configuration files from their .bak files or the domain backup.

  4. Restore the previous server/network configuration if required.

  5. Restart WebLogic.

  6. Validate the environment.

For individual startup.properties files:

cp startup.properties.bak startup.properties

For a complete domain rollback, restore the WebLogic domain from the backup created before the change.

18. Change Management Summary

The recommended sequence is:

Validate New IP → Stop WebLogic → Backup Domain → Search Old IP → Update Required Configuration → Validate Configuration → Start WebLogic → Validate WebLogic → Validate Applications → Close Change

Key Principle

Do not perform a blanket IP replacement across the WebLogic domain. Identify each reference to the old IP and update only the configuration entries that are required for the server IP change.