title: Can we use public cert. for AWS Site-to-Site VPN Tunnel Authentication?
body: <p>Since private CA cert. cost $400 per month, can we use the public cert. instead?</p>
  <p>Can we use acm public ca to identify ipsec Site-to-Site vpn endpoints?</p>
  <p>Is there any restriction/limitation and cons on using public cert.? Thanks.</p>