Does Web Security Service accept ICMP through a tunnel to a data center?

Products

• Cloud Secure Web Gateway - Cloud SWG

Issue/Introduction

When using a Palo Alto firewall, can ICMP be used to know if the tunnel is up and active?

Environment

Palo Alto 

Web Security Service

Resolution

The data center will respond to ICMP to allow an administrator to set policy that the tunnel is no longer active.