When I go to the purepaths and add column client IP,I am seeing all the requests coming from same IP.can someone help me to understand is this client IP is from actual user or client IP from firewall?
It depends on what headers are visible in the PurePath. If by the time it gets to the agent the request only has a firewall or other network device IP address then that is what will be used but if there is a header with a better representation of the client IP it will use that.
If you go into server settings -> geographical locations you can see what request headers are used and their priority (i.e. the top ones will overrule any lower ones). The highest priority one that is found is what will be used as the client IP in the PurePath: