Cloud Computing is buzzword in market now days. It has been developed to reduce the overall expenses as it provides the on demand services at any time on pay-per-use pattern. Internet is the medium for deploying cloud computing services for users to access the required application and services . It allows the users to access the services which are actually not reside in their own data centers. It provides an efficient and very flexible way for the services, applications to meet business needs. Its infrastructure consist three layers- IAAS, PAAS and SAAS. Cloud computing deploy its services through:- Private, Public and Hybrid Cloud. As the Cloud Computing is still on its initial stage of development and can say in its growing phase, so it suffers from various threats, attacks and vulnerabilities that sometime prevent the user, customers from trusting on it. User's sensitive data resides on Cloud, but due to its lack of security control the confidential data of the clients are comes under the risk of malicious activities or the unauthorized access from illegal users. So it needs an efficient method for ensuring security. In this paper it is recommend to use of Firewalls and VPN_Firewall (virtual private network) in cloud networks for its security. There is a performance evaluation of OSPF, IGRP and EIGRP protocols under two scenarios- with Firewall, and VPN_Firewall.

Firewall VPN EIGRP OSPF IGRP Cloud Computing.