xclock dbca PuTTY X11 proxy: Authorisation not recognised

PuTTY X11 proxy: Authorisation not recognised

Error: Can't open display: localhost:10

Error:

[dbadmin53@brvmoracle ~]$ sudo su - oracle

Last login: Wed Dec 16 09:43:51 +03 2020 on pts/0

[oracle@brvmoracle ~]$ xclock

PuTTY X11 proxy: Authorisation not recognised

Error: Can't open display: localhost:10

or 

[oracle@brvmoracle ~]$ dbca

PuTTY X11 proxy: Authorisation not recognised

Exception in thread "main" java.lang.NoClassDefFoundError: Could not initialize class sun.awt.X11.XToolkit

        at java.lang.Class.forName0(Native Method)

        at java.lang.Class.forName(Class.java:264)

        at java.awt.Toolkit$2.run(Toolkit.java:860)

        at java.awt.Toolkit$2.run(Toolkit.java:855)

        at java.security.AccessController.doPrivileged(Native Method)

        at java.awt.Toolkit.getDefaultToolkit(Toolkit.java:854)

        at com.jgoodies.looks.LookUtils.isLowResolution(LookUtils.java:484)

        at com.jgoodies.looks.LookUtils.<clinit>(LookUtils.java:249)

        at com.jgoodies.looks.plastic.PlasticLookAndFeel.<clinit>(PlasticLookAndFeel.java:135)

        at java.lang.Class.forName0(Native Method)

        at java.lang.Class.forName(Class.java:348)

        at javax.swing.SwingUtilities.loadSystemClass(SwingUtilities.java:1874)

        at javax.swing.UIManager.setLookAndFeel(UIManager.java:582)

        at oracle.install.commons.util.Application.startup(Application.java:917)

        at oracle.install.commons.flow.FlowApplication.startup(FlowApplication.java:181)

        at oracle.install.commons.flow.FlowApplication.startup(FlowApplication.java:198)

        at oracle.assistants.common.base.driver.AssistantApplication.startup(AssistantApplication.java:320)

        at oracle.assistants.dbca.driver.DBConfigurator.startup(DBConfigurator.java:342)

        at oracle.assistants.dbca.driver.DBConfigurator.main(DBConfigurator.java:386)

[oracle@brvmoracle ~]$

Reason:

Switching from 'dbadmin53' user to 'oracle' user - causing the error.

Try login with oracle user directly from putty.

ping multiple ip addresses from windows PowerShell script cmd

### save iplist in a txt file as "iplist.txt"

### save the script as "PingIP.ps1" ( powershell script )

### rightclick and choose "Run with PowerShell"

$names=Get-content "D:\tasks\Ping\iplist.txt"

foreach($name in $names){

if(Test-Connection -ComputerName $name -Count 2 -ErrorAction SilentlyContinue){

Write-Host "$name is up" -ForegroundColor Green

$output+="$name is up,"+"`n"

}

else{

Write-Host "$name is --------&gt; down" -ForegroundColor Red

$output+="$name is --------&gt; down,"+"`n"

}

}

$output | Out-File "D:\tasks\Ping\result.txt"

Start-Sleep -s 30

### iplist.txt ( without tab or space at end of line)

172.21.80.3

172.21.80.4

172.21.80.60

172.21.80.61

172.21.11.115

172.21.11.43

172.21.30.5

localhost

### result.txt ( looks like below )

172.21.80.3 is up,

172.21.80.4 is up,

172.21.80.60 is --------> down,

172.21.80.61 is up,

172.21.11.115 is up,

172.21.11.43 is up,

172.21.30.5 is up,

localhost is up,