Hi Sumit,
Actually, I just got it working without forwarding card:
yum install -y pam_ssh_agent_auth
~/.ssh/config:
ForwardAgent yes
/etc/sudoers:
Defaults env_keep += "SSH_AUTH_SOCK"
/etc/pam.d/sudo:
#%PAM-1.0
auth sufficient pam_ssh_agent_auth.so
authorized_keys_command=/usr/bin/sss_ssh_authorizedkeys
auth include system-auth
account include system-auth
password include system-auth
session include system-auth
systemctl restart sshd
systemctl restart sssd
[user@local][~]$ ssh ipaclient
[user@ipaclient][~]$ sudo -i
[root@gs66-ipaclient][~]#
Thanks for your time!
-Leon