Update patch information in redhat portal

 If the redhat operating system servers are registered in redhat portal with subscription, It Periodically scans  the server and updates the information in the portal. 

Once the patches are applied in the server, to sync the report forcelly, Execute the below command.

service rhsmcertd stop

rhsmcertd --now

service rhsmcertd start

Alternative tool for xming

 xming started charging to use xming tool. Hence, We use the below tool with free of cost. There are so many tools available in market. But, this tool is so easy to configure.

Link :-

How do I set up X11 forwarding? (upenn.edu)

Download [Portable Format ]: 

MobaXterm Xserver with SSH, telnet, RDP, VNC and X11 - Home Edition (mobatek.net)

Unzip the folder and run "MobaXterm_Personal_22.1" tool.

Login to the linux server and execute the below command.

export DISPLAY="<Desktop IP>:0.0"

Example:

export DISPLAY="192.24.40.2:0.0"

run "xclock" command to confirm whether you can see the GUI.

connection timeout with smtp server

Issue: 

 I have faced this issue after I did inplace upgrade from OEL 6 to OEL 7. I am not able to send email and the maillog [/var/log/] updated with below error. 

 node-02 sendmail[27436]: 27E5KQWW098928: to=, ctladdr= (1001/1001), delay=00:20:52, xdelay=00:00:00, mailer=esmtp, pri=480584, relay=test.com., dsn=4.0.0, stat=Deferred: Connection timed out with test.com. 

node-02 sendmail[27544]: 27E5eOXd027538: to=, ctladdr= (1001/1001), delay=00:01:00, xdelay=00:01:00, mailer=esmtp, pri=120584, relay=test.com. [192.23.6.77], dsn=4.0.0, stat=Deferred: Connection timed out with test.com.

Reason For this issue: 

In our infra, our mail server dns name is “mail.test.com” and there is separate server for hosting one website called “test.com”. Due to that, If I use “mail.test.com”, The linux server resolves “test.com” instead of “mail.test.com” and ended with timeout error.

Solution: 

Update the IP instead of dns in the configuration. 

• systemctl stop sendmail 

• vi /etc/mail/sendmail.mc 

• Add the below entry [replace the hostname with IP] 

            o define(`SMART_HOST', `192.168.10.111')dnl 

• m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf 

• systemctl restart sendmail 

 If the same issue happens, do the below steps and restart sendmail services.

 • grep DS /etc/mail/sendmail.cf 

Sample output: DS192.168.10.111 If there is no IP, add mail server IP.