Vpn with Ipsec

1. Abstract The goal of VPNs is to provide a cost-effective and secure demeanor to yoke business to one an new(prenominal) and far drubers to office engagements. Ne 2rk Security protocols encompasses the basis for natural rubber & reli commensurate entropy transfer. These certification devices should be fitting to provide accountability, access suss out, confidentiality, integrity, while all the prison term organism cost effective. This provides us with different certification protocols related to the transfer of info finished a ne twainrk.With a prevalent brass of nedeucerks the frontier for world info communication, it is absolutely critical to be able to countenance these protocols provide the most secure run possible. In this report technical review IPSec protocol involved with Network Security. Internet communications protocol Security (IPSec) It is a suite of protocol for securing IP communication theory by authentication and encoding of for each one IP softw be establishment of a communication session. IPSec also includes protocols for paying unwashed authentication amongst agents at the beginning of the session and negotiating coding traces which is to be procedure during the session.IPSec is an revoke to oddity security scheme operating in the Layer of Internet of the IP suite. It brush aside be utilize in defend data flows between a pair of hosts, between a pair of security portals, or between a security gateway and a host. 2. Introduction to VPN A VPN is a practical(prenominal) occult earnings, which is built on top of brisk physical network that give the sack provide a secure communication mechanism for data and former(a) study transmitted between networks. Beca affair VPN hatful be employ over existing networks, such as the Internet, it shadow facilitate the secure transfer of crank data across public networks.This is often less expensive than alternatives such as employ toffee-nosed telecommunic ations lines between organizations or branch offices. VPNs female genitalia also provide flexible solutions, such as securing communications between removed(p) telecommuters and the organizations servers, regardless of where the telecommuters argon located. A VPN can even be established within a single network to protect particularly sensitive communications from otherwise parties on the selfsame(prenominal) network. It is important to understand that VPNs do non remove all risk of infection from networking.While VPNs can greatly reduce risk, particularly for communications that occur over public networks, they cannot remove all risk for such communications. One problem is the strength of the implementation. For practice, flaws in an graveion algorithmic rule or the softw are implementing the algorithm could allow assailants to decrypt intercepted traffic stochastic number generators that do not produce sufficiently random determine could provide additional attack possib ilities. Another issue is encryption diagnose disclosure an attacker who discovers a mention could not however decrypt traffic but potentially also poses as a legitimate user.Another area of risk involves availability. A common model for information assurance is establish on the concepts of confidential, integrity, and availability. Although VPNs are designed to support confidentiality and integrity, they generally do not improve availability, the ability for accepted users to access systems as needed. In fact, many VPN implementations truly tend to decrease availability somewhat, because they add to a greater extent components and services to the existing network infrastructure. This is highly dependent upon the chosen VPN architecture model and the details of the implementation. 3. 1 VPN TechnologiesThe Internet is a divided public network of networks with open transmission protocols. Therefore, VPNs must include measures for packet encapsulation ( cut intoing), encryption, and authentication to warrant that sensitive data reaches its destination without modifying by unauthorized parties. digit IP software program 2. 2 burrows The thing that makes a Virtual Private Network virtually private is kn stimulate as tunnel. Even though you access your network via Internet, youre not really on the Internet, you are actually on your company network. Although the term tunnel feels like its describing a fixed path through the Internet, this is not the case.As with any Internet traffic, VPN tunnel packets may scram different paths between the two depots. 2. 3 Encryption Encryption is a technique for scrambling and unscrambling information. The information which is unscrambled is called clear-text, and the information which is scrambled is called cipher-text. At either end of your VPN tunnel sits a VPN gateway in hardware of software form. The gateway at sending post encrypts the information into cipher text before sending the encrypted information through the tunnel over the Internet. The VPN gateway at receiving location decrypts the information back into clear-text. . 4 let outs A see is the secret code that the encryption algorithm uses to give a unique strain of cipher-text. To put it in simpler terms, two people expertness go to the hardware store and buy the same lock off the shelf, but their combinations are different. In VPN encryption, the system may be the same (like the lock), but our let outs are different (like the combination). Of course, VPN locks have a sess more than three numbers on the dial combination. As a matter of fact, transmission security strength depends on the length of the keys which you use. Heres the formula 8-bit keys = 256 combinations or two to the eighth actor (28) 16-bit keys = 65,536 combinations or two to the 16th power (216) 56-bit keys = 72,057,594,037,927,900 or two to the 56th power (256) And so on In other words, if you utilize a 16-bit key, a fake attacker might have to make 65 ,536 attempts at cracking your combination. Obviously, this would be a quick and simple task for computers. Thats why a dowery of VPN products on the market today are apply 168-bit keys, creating 374,144, 419,156,711,000,000,000,000,000,000,000,000,000,000,000,000 Possible combinations.There are some enterprises out on that point going even higher. Even the fastest computers today would need extended time to crack a code that is complex. You might be tempted to make a policy of always using the highest-bit encryption method available, but keep in mind that processing such complicated cipher-text lead require significant, dedicated CPU processing power. There are other ways to use keys to the outmost security to extend your needs. For example, it does, indeed, take time to crack the higher-bit keys. If you establish a policy of periodically changing your keys, the trespassers wont be able to keep up. . 4. 1 Symmetrical Keys Symmetrical keys means the same key is utilise at each end of the tunnel to encrypt and decrypt information. Because a symmetrical key is being shared by both parties, there must be an understanding between the two to take appropriate steps to keep the key secret, which is why symmetrical keys are often referred to as shared secrets. These keys come more difficult to distribute, since they must be kept confidential. A technique called key split up may be employed to reduce the potential of key disclosure during transit.This allows participants to use public carry such as the Internet. More comm yet, however, distribution of symmetrical keys is more of a manual operation using paper, removable media, or hardware docking. 2. 4. 2 Asymmetrical Keys Asymmetrical keys are slightly more complicated, but, logistically, practically easier to manage. Asymmetrical keys allow information to be encrypted with one key and decrypted with a different key. The two keys used in this scenario are referred to as private and public keys, or the ones you keep to yourself and the ones you distribute to your out-of-door users.Consider this example Lets call our business FQT and HIQT. FQT has a set of two keys, a public key and a private key. His public key has been programmed to encrypt data so that further if his own private key can decipher it. In order to communicate securely, FQT hands his public key to HIQT and tells him to encrypt anything he sends with that code. Using this asymmetrical keying method, both are assured that only FQT will be able to testify those transmissions because he retains the private decoder key. If the communication is to be bi-directional, HIQT would share his public key with FQT in the same manner. . 5 Key Management Configuring pre-shared secrets in smaller VPNs does not necessarily require software automation or large infrastructure investments. However, larger networks might benefit from deploying a Public Key Infrastructure (PKI) to create, distribute, and track digital certificates on indi vidual-user basis. You can use pre-shared keys or digital signatures if your equipment supports these authentication alternatives. However, if you root to use certificates, there are options. For example, you may use third-party Certificate Authority services.Or, you may build your own Certificate Authority using software from Entrust, Xcert, or Baltimore Technologies. Either option will help you establish a comprehensive PKI, which is especially useful in large organizations needed to extend secure, limited network access beyond their own internal users to business partners and customers. 2. 6 certificate The last bit of hold involved in VPN transmission is authentication. At this step, recipients of data can determine if the sender is really who he says he is (User/System certification) and if the data was redirected or corrupted enroute (Data Authentication). . 6. 1 User/System Authentication Consider, again, our two business named FQT and HIQT. When FQT receives a contented ness signed from HIQT, FQT picks a random number and encrypts it using a key which only HIQT should be able to decode. HIQT then decrypts the random number and re-encrypts it using a key only QT should be able to decode. When FQT gets his number back, he can be assured it is really IQT on the other end. 2. 6. 2 Data Authentication In order to verify that data packets have arrived unaltered, VPN systems often use a technique involving hash functions. A hash function creates a sort of fingerprint of the airplane pilot data. It calculates a unique number, called a hash, based on fixed or variable length values of unique bit strings. The sender attaches the number to the data packet before the encryption step. When the recipient receives the data and decrypts it, he can calculate his own hash independently. The output of his calculation is compared to the stored value appended by the sender. If the two hashes do not match, the recipient can be able to as plazae the data has been altere d. 3.VPN Protocols used for tunneling 3. 1 IPSec IPSec is a amount for secure encrypted communication that provides two security methods Authenticated drumheads (AH) and Encapsulating Security Payload ( extrasensory perception). AH is used to authenticate packets, whereas clairvoyance encrypts the data portion of packets. It can work in two different modes capture mode and tunnel mode. IPSec is commonly combined with IKE as a means of using public key cryptography to encrypt data between local area networks or between a node and a LAN. IKE provides for the step in of public and private keys. 3. 2 PPPIn networking, the Point-to-Point Protocol (PPP) is commonly used in establishing a direct association between two networking nodes. It can provide have-to doe withion authentication, transmission encryption, and compression. 3. 3 L2TP Layer 2 Tunneling Protocol (L2TP) is an extension of the long protocol used to establish dial-up lodges on the Internet, Point-to-Point Protocol (PPP). L2TP uses IPSec rather than MPPE to encrypt data sent over PPP. 3. 4 PPTP Point-to-Point Tunneling Protocol (PPTP) is commonly used by away users who need to connect to a network using a dial-in union of modem.PPTP uses Microsoft Point-to-Point Encryption (MPPE) to encrypt data that passes between the remote computer and the remote access server. 3 Technical Review of IPSec over VPN 4. 1 IPSec IPSec is the Internet standard protocol for tunneling, encryption, and authentication. It was designed to protect network traffic by speaking basic usage issues including- Access control Connection integrity Authentication of data origin Protection against replays Traffic flow confidentiality The IPSec protocol allows two operational modes.In Transport mode, everything croupe the packet and not including the IP header is protected. In Tunnel mode, everything behind and including the header is protected, requiring a new pseudo IP header. While the IPSec protocol was under develo pment, two other protocols L2TP and PPTP used as temporary solutions. L2TP (Layer 2 Tunneling Protocol) encloses non-Internet protocols such as IPX, SNA, and AppleTalk inside an IP envelope. However, L2TP has to rely on other protocols for encryption functions. PPTP (Point-to-Point Tunneling Protocol) is a proprietary Microsoft encryption and authentication protocol.Although originally developed as a temporary solution, Microsoft continues to deploy L2TP as its tunneling protocol instead of IPSec tunneling. When comparing the three, IPSec is, the most widely used protocol, and the only one that solicites future VPN environments (such as new IP protocols). 4. 1. 2 IPSec Architecture The architecture of the IPSec implementation refers to the excerption of device and software to provide IPSec services and the placement of IPSec endpoints within the existing network infrastructure.These two considerations are often closely tied unitedly For example, a decision could be made to use the existing Internet firewall as the IPSec gateway. This section will explore three particular aspects of IPSec architecture- gateway placement, IPSec client software for hosts, and host process space management. fig Gateway-to-Gateway VPN for Remote Office Connectivity 4. 1. 3 IPSec Functions Internet Protocol Security (IPSec) has emerged as the most commonly used network layer security control for protecting communications. IPSec is a framework of open standards for ensuring private communications over IP networks.Depending on how IPSec is implemented and tack together, it can provide any combination of the following types of protection Confidentiality. IPSec can visit that data cannot be read by unknow parties. This is accomplished by encrypting data using a cryptographic algorithm and a secret key. A value known only to the two parties exchanging data. The data can only be decrypted by someone who has the secret key. Integrity. IPSec can determine if data has been changed ( intentionally or unintentionally) during transit. The integrity of data can be assured by enerating a message authentication code (MAC) value, which is a cryptographic checking sum of the data. If the data is altered and the MAC is recalculated, the old and new MACs will be different. ally Authentication. Each IPSec endpoint confirms the identity of the other IPSec endpoint with which it wishes to communicate, ensuring that the network traffic and data is being sent from the expected host. instant replay Protection. The same data is not delivered multiple times, and data is not delivered grossly out of order. However, IPSec does not ensure that data is delivered in the exact order in which it is sent.Traffic Analysis and Protection. A person monitoring network traffic does not know which parties are communicating, how often communications are occurring, or how much data is being exchanged. However, the number of packets being exchanged can be counted. Access Control. IPSec endpoin ts can perform filtering to ensure that only authorized IPSec users can access particular network resources. IPSec endpoints can also allow or block certain types of network traffic, such as allowing Web server access but denying buck sharing. 4. 1. 4 IPSec FundamentalsIPSec is a collection of protocols that assist in protecting communications over IP networks. IPSec protocols work together in various combinations to provide protection for communications. The three primary components of the IPSec protocol that provides the protections for the communication are ESP, AH and IKE. Encapsulating security Payload (ESP) ESP is the second core IPSec security protocol. In the initial version of IPSec, ESP provided only encryption for packet payload data. It can perform authentication to provide integrity protection, although not for the outermost IP header.Also, ESP. s encryption can be disabled through the Null ESP Encryption Algorithm. Therefore, in all but the oldest IPSec implementation s, ESP can be used to provide only encryption encryption and integrity protection or only integrity protection Authentication Header (AH) AH, one of the IPSec security protocols provides integrity protection for packet headers and data, as hale as user authentication. It can optionally provide replay protection and access protection. AH cannot encrypt any portion of packets.In the initial version of IPSec, the ESP protocol could provide only encryption, not authentication, so AH and ESP were often used together to provide both confidentiality and integrity protection for communications. Because authentication capabilities were added to ESP in the second version of IPSec AH has become less significant in fact, some IPSec software no longer supports AH. However, AH is still valuable because AH can authenticate portions of packets that ESP cannot. Internet Key Exchange (IKE) The bearing of the Internet Key Exchange (IKE) protocol is to negociate, create, and manage security associat ions.Security association is a generic term for a set of values that prepare the IPSec features and protections applied to a connection. It can also be manually created, using values agreed upon in advance by both parties, but these security associations cannot be updated this method does not scale for a real-life large-scale VPNs. In IPSec, IKE is used to provide a secure mechanism for establishing IPSec-protected connections. 4. 1. 5 IPSec Protocol fundamental principle Transport mode is used to provide secure communications between hosts over any vagabond of IP addresses.Tunnel mode is used to create secure links between two private networks. Tunnel mode is the obvious choice for VPNs however, there are some concerns about using tunnel mode in a client-to-site VPN because the IPSec protocol by itself does not provide for user authentication. However, when combined with an authentication system like Kerberos, IPSec can authenticate users. 4. 1. 6 Cryptography Used in IPSec Sess ions Cryptography policy involves choosing encryption and integrity protection algorithms and key lengths. Most IPSec implementations offer the HMAC-MD5 and HMAC-SHA-1 hashing algorithms.Neither of these algorithms is computationally intensive. Although both plain MD5 and plain SHA-1 have known weaknesses, both are still considered sufficiently secure in their HMAC versions. In some implementations of IPSec, the cryptography policy settings are not immediately apparent to admin. The default settings for encryption and integrity protection, as well as the details of each setting, are often located down several levels of carte du jours or are split among multiple locations. It is also challenging with some implementations to alter the settings once they have been located. . 1. 7 Authentication Used for Identifying IPSec IPSec implementations typically support two authentication methods pre-shared keys and digital signatures. To use pre-shared keys, the IPSec admin creates a key or pa ssword string, which is then configured in each IPSec device. Pre-shared keys are the simplest authentication method to implement, but key management is challenging. Because of scalability and security concerns, pre-shared key authentication is generally an acceptable solution only for small-scale implementations with known IP addresses or small IP address plucks.In the digital signature method, a certificate identifies each device, and each device is configured to use certificates. Two IPSec endpoints will trust each other if a Certification Authority (CA) that they both trust has signed their certificates. Many organizations are currently implementing public key infrastructures (PKI) for managing certificates for IPSec VPNs and other applications such as secure e-mail and Web access. 5. Conclusion VPNs allow users or corporations to connect to remote servers, branch offices, or to other companies over internetwork of public, while maintaining secure communications.In all of these cases, the secure connection appears to the user as a private network communicationdespite the fact that this communication occurs over internetwork of public. VPN technology is designed to address issues surrounding the current business trend toward increased telecommuting and widely distributed global operations, where workers must be able to connect to central resources and communicate with each other. This paper provides an overview of VPN, VPN over IPSec and describes the basic requirements of useful VPN technologies user authentication, address management, data encryption, key management, nd multiprotocol support. 6. Reference 1. S. Farnkel, K. Kent, R. Lewkowski. (December 2005). Guide to IPSec VPN. forthcoming http//csrc. nist. gov/publications/nistpubs/800-77/sp800-77. pdf. Last accessed January 20 2011. 2. Tom Olzak. (Jan22, 2007). SSTP Microsoft VPN. Available http//www. techrepublic. com/blog/security/sstp-microsofts-vpn/149. Last accessed 25 January 2011. 3. give way VPN. (2011). Open VPN cryptographic layer. Available http//openvpn. net/index. php/open-source/documentation/security-overview. html. Last accessed 28 January 2011. 4. Erik Rodrigues-Types of VPN online. Resources as well as Images) Available from http//www. skullbox. net/vpn. phpAccessed on Feb 12 2011 5. Internet Protocol Security online. Available from http//www. interpeak. com/files/ipsec. pdfAccessed on Feb 4 2011 6. SSL VPN VS. IPSec VPN online. Available from http//www. arraynetworks. net/ufiles/File/SSLVPNvsIPSecWhitePaper021006. pdfAccessed on January 29 2011 7. Available from http//www. windowsecurity. com/articles/VPN-Options. htmlAccessed on Feb 14 2011 8. Download the kB Bow IPSec VPN client online. Available from www. thegreenbow. com/vpn/vpn_down. html Accessed on Feb 2012 . YouTube video of using the Green Bow software Available from http//www. youtube. com/watch? v=m6fu6saaNhQ Accessed on Jan 29 2008 7. Appendix The step by step frame-up of The Green Bow IPSec VP N client is described below. Running the setup file. Language screen appears and andiron OK. Fig Choose language screen. Welcome screen appears and click next. Fig Setup Welcome screen. License and information regarding licenses then click I Agree. Fig License and information screen. Install location screen appears and click next. Fig Installation location screen. Choosing start menu folder screen appears and click Install.Fig start menu folder screen. Installing screen appears. Fig Installing setup screen. Windows Security screen appears and click install. Fig Windows Security screen. Setup Complete screen appears and click finish Fig Completing Setup screen. How to use This Software System Tray Icon VPN material body Three step Configuration Wizard ill-use 1 of 3 Choice of remote equipment You must specify the type of the equipment at the end of the tunnel VPN gateway. Step 2 of 3 VPN tunnel parameters You must specify the following information the public (network side) address of the remote gateway he preshared key you will use for this tunnel (this preshared key must be the same as key in the Gateway) the IP address of your company LAN (e. g. specify 192. 168. 1. 0) Step 3 of 3 Summary The third step summaries your new VPN configuration. Other parameters may be further configured directly via the Configuration Panel (e. g. Certificates, virtual IP address, etc). VPN Tunnel Configuration How to create a VPN Tunnel? To create a VPN tunnel from the Configuration Panel (without using the Configuration Wizard), you must follow the following steps 1. Right-click on Configuration in the list window and select New word form 1 2.Configure Authentication human body (Phase 1) 3. Right-click on the new Phase 1 in the tree control and select Add Phase 2 4. Configure IPSec Phase (Phase 2) 5. Once the parameters are set, click on Save Apply to take into account the new configuration. That way the IKE service will run with the new parameters 6. Click on Open Tunnel for establishing the IPSec VPN tunnel (only in IPSec Configuration window) VPN Configuration Please refer to Phase 1 and Phase 2 for settings descriptions. Authentication or Phase 1 What is Phase 1? Authentication or Phase 1 window will concern settings for Authentication Phase or Phase 1.It is also called IKE Negotiation Phase. Phase 1s purpose is to negotiate IKE policy sets, authenticate the peers, and set up a secure channel between the peers. As part of Phase 1, each end system must identify and authenticate itself to the other. Interface Network interface IP address of the computer, through which VPN connection is established. Remote Gateway IP address or DNS address of the remote gateway (in our example gateway. domain. com). This plain stitch is necessary. Pre-shared key Password or shared key with the remote gateway. IKE Encryption algorithm used during Authentication phase (DES, 3DES, AES, AES128, AES192, AES256).Authentication algorithm used during Authentication phase ( MD5, SHA-1, SHA-256). Key group is key length. Phase1 Advanced Settings description Config-Mode If it is checked, the VPN Client will activate Config-Mode for this tunnel. Config- Mode allows VPN Client to fetch some VPN Configuration information from the VPN gateway. If Config-Mode is enabled, and provided that the remote Gateway supports, the following Parameters will be negotiated between the VPN Client and the remote Gateway during the IKE exchanges (Phase 1) Virtual IP address of the VPN Client DNS server address (optional)WINS server address (optional) Aggressive Mode If checked, the VPN Client will used aggressive mode as negotiation mode with the remote gateway. IPSec Configuration or Phase 2 What is Phase 2? IPSec Configuration or Phase 2 window will concern settings for Phase 2. The purpose of Phase 2 is to negotiate the IPSec security parameters that are applied to the traffic going through tunnels negotiate during Phase 1. Phase 2 Settings Description VPN Client address Virtual IP address used by the VPN Client inside the remote LAN The computer will appear in the LAN with this IP address.It is important this IP address should not belong to the remote LAN (e. g. , in the example, you should exclude an IP address like 192. 168. 1. 10). Address type The remote endpoint may be a LAN or a single computer, In case the remote endpoint is a LAN, convey Subnet address or IP Range. When choosing Subnet address, the two fields Remote LAN address and Subnet mask become available. When choosing IP Range, the two fields Start address and End address become available, enabling TheGreenBow IPSec VPN Client to establish a tunnel only within a range of a predefined IP addresses.The range of IP addresses can be one IP address. Incase the remote end point is a single computer, choose Single Address. When choosing Single address, only Remote host address is available. Remote address This field is Remote LAN address depending of the address type. It is the remote IP address or LAN network address of the gateway that opens the VPN tunnel. Phase2 Advanced Settings hired hand configuration Scripts or applications can be enabled for each step of a VPN tunnel opening and remainder process Before tunnel is opened Right after the tunnel is opened Before tunnel closes Right after tunnel is closedRemote Sharing Global Parameters Lifetime (sec. ) Default sprightliness for IKE rekeying. Minimal lifetime for IKE rekeying. Maximal lifetime for IKE rekeying. Default lifetime for IPSec rekeying. Maximal lifetime for IPSec rekeying. Minimal lifetime for IPSec rekeying. Dead Peer Detection (DPD) Check interval (sec. ) Interval between DPD messages. Max number of retries Number of DPD messages sent. Delay between retries (sec. ) Interval between DPD messages when no reply from remote gateway. Miscellaneous Retransmissions How many times a message should be retransmitted before giving up. USB Mode Step 1 Step2 Step3 Step4