EC2 Security Group not connecting to my IP - amazon-web-services

Question

Seems like a basic job, but for some reason it is not working for me. I wish to access my EC2 instances from my office IP only.
I went into my security group and added an SSH rule with source for my IP only like this -
But this does not seems to be working for me at all. I get connection denied when I try to connect via WinSCP or by using terminal.
Everything works if I change my source to Everywhere (0.0.0.0/0)
Anyone has any pointer for me please.

Answer 1

Login to the EC2 using the method that works and issue the command
who am i
It will say something like
ec2-user pts/0 2016-02-29 15:06 (104.66.242.192)
Use the ip address shown for you (not the one above) in the security group rule

Answer 2

Although "who am i" work fine. However I'd like to add two more solutions.
both are very easy.
Solution 1:
Step 1: Open security group for all IP's (0.0.0.0/0) for a while.
Step 2: Make ssh connection to your server.
Step 3: run "w" command and check the output in FROM column.
ubuntu#ip-172-31-39-228:~$ w
23:20:09 up 5 min, 1 user, load average: 0.08, 0.08, 0.04
USER TTY FROM LOGIN# IDLE JCPU PCPU WHAT
ubuntu pts/0 52.95.75.17 23:20 0.00s 0.01s 0.00s w
Step 4: Replace this IP in the security group with 0.0.0.0/0 ( like 52.95.75.17/32 ).
Solution 2:
Step 1: Open security group for all IP's (0.0.0.0/0) for a while.
Step 2: Make ssh connection to your server.
Step 3: Check the last login info on welcome message.
like :
Learn more about enabling ESM Apps service at https://ubuntu.com/esm
Last login: Thu Feb 9 23:21:42 2023 from 52.95.75.17
ubuntu#ip-172-31-39-228:~$
ubuntu#ip-172-31-39-228:~$
Step 4 ( optional ): If IP address not available in welcome message. Then run "last" command.
ubuntu#ip-172-31-39-228:~$
ubuntu#ip-172-31-39-228:~$ last
ubuntu pts/2 52.95.75.17 Thu Feb 9 23:33 still logged in
ubuntu pts/1 52.95.75.17 Thu Feb 9 23:21 still logged in
Step 5: Replace this IP in the security group with 0.0.0.0/0 ( like 52.95.75.17/32 ).
Check below screenshot for reference of above solutions:

Answer 3

Feel free to use my powershell script for this .
The script detects your public ip and adds it to the inbound security group rules of dedicated RDP and SSH security groups .
If these groups do not exist , the script will create them and add it to the appropriate instances .
https://github.com/manuelh2410/public/blob/1/AWSIP_Linux_Win.ps1