MPLS is the protocol framework on which the attention of network service provider is focused as it provides privacy and unbreakable security to the users. Recently, VPNs based on MPLS have achieved quite great progress. MPLS VPN through ISP network is easier and faster. But with the development of internet technology the self security of MPLS VPN now cannot meet the enhanced requirement of the network security. So, taking the advantage of IPSec protocol for data encrypting, the security scheme of VPN is enhanced. Recent advances in Virtual Private Network (VPN) offer great benefits to network managers, especially in terms of cost savings. VPN networks based upon IP Security (IPSec) along with a combination of MPLS is a viable alternative that is growing in popularity.Security of MPLS is a major issue There are various attacks which can break the security of MPLS technology. For example a brute force attack is a strategy used to break the confidentiality of data in MPLS Technology. So Encryption Algorithms like AES , DES, TDES which is a part of IPSec are used to secure MPLS technology against various attacks.