# Avoid sending public keys to SSH servers by default

# cat .ssh/config
Host *
 IdentitiesOnly yes
 PubkeyAuthentication no

#Host example1
# Hostname ssh.example1.org
# Port 22
# User test


#Host example2
# Hostname ssh.example2.org
# IdentityFile ~/.ssh/example2_id_rsa
# PubkeyAuthentication yes

# ssh-keygen -t rsa -b 2048 -C test@ssh.example2.org -f ~/.ssh/example2_id_rsa
Generating public/private rsa key pair.
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in ~/.ssh/example2_id_rsa.
Your public key has been saved in ~/.ssh/example2_id_rsa.pub.
The key fingerprint is:
4d:4b:d5:3c:ca:db:ed:b4:2b:6f:6e:3d:74:32:f3:31 test@ssh.example2.org

Reference

https://github.com/FiloSottile/whosthere#how-do-i-stop-it