History Of Why Use Tunneling

Published Date: 02 Nov 2017

qwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmrtyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmrtyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmrtyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmrtyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmrtyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmrtyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmrtyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnmqwertyuiopasdfghjklzxcvbnm

Network Design

Coursework 1

B00205468

Contents

Introduction

In this report I will be describing and explaining what tunneling is and why it is used. I will also be discussing some of the different tunneling protocols and explaining the advantages and disadvantages of these tunneling protocols. The different tunneling protocols I will be discussing are PPTP, L2TP and SSH. I will also show the links between these different tunneling protocols and detail the tunneling standards.

WHat is Tunneling?

Tunneling is a network protocol that sends packets using another networks connections. This connection is usually encrypted by using encapsulation. A protocol is termed as tunneling if it appears as if it makes its way through he different types of protocols. It is used to transmit a large volume of protocols through a network. Some tunneling protocols operate at layer 4, this is the transport layer which means that the tunneling protocol would replace UDP and TDP. Others work at layer 2, the data-link layer which encapsulates and encapsulates the packets.

Why use tunneling

Tunneling has many benefits such as transporting payloads over incompatible delivery networks. It is useful for providing a safe way to move through an un-trusted network. Another advantage is the use of data encryption for the purpose of transmitting a susceptible payload through a public network. The most significant advantage being that it allows VPNs to be created over a public network which will save costs felt by both service providers who make more money from VPN customers and end users who will not have to create dedicated networks. Other advantages include improved security due to encapsulation.

Tunneling Protocols

The three Tunneling protocols that I will be describing and explaining are Point-to-Point Tunneling Protocol (PPTP), Layer 2 Tunneling Protocol (L2TP) and Secure Socket Tunneling Protocol (SSTP).

Point-To-Point Tunneling Protocol (PPTP)

Point-to-Point Tunneling Protocol (PPTP) is a multiprotocol, that works on the data link layer. It is used for the secure transport of data from a remote client on a public network to a private network by using a Virtual Private Network (VPN). It uses Password authentication Protocol(PAP) or Challenge-Handshake Authentication Protocol (CHAP) for authenticating the link before the transmitting data. (Anon., n.d.)' this means that there is lower level congestion and flow control due to the use of tunnels compared to PPP. PPTP provides more efficient use of the bandwidth that is available and avoids retransmissions of data that isn't required.

How it works

http://www.zdh1909.com/UploadFiles/2011-09/lpz/20110908202430241.jpg (Anon., n.d.)

PPTP works by storing data inside the PPP packets and then stores those packets inside an IP packet for transportation to its destination. PPTP has the option for compression and encryption of the packets. GRE is used by PPTP to send and receive data. PPTP works by dividing all the data that is to be transmitted into two types of messages - data and control.

PPTP Security

PPTP has the option to encrypt, authenticate and filter packets. It uses PAP and CHAP for authentication and PPP for authentication of users, maintaining and encrypting the user connections.

Advantages

PPTP uses GRE to transport user PPP packets improves lower level flow control and helps with data congestion. Splitting the data into the two different types of messages makes PPTP simpler to use and manage as it means that PPTP can send messages over multiple protocols. Another advantage is that is easy to setup and is commonly found. It also takes up a very small volume of bandwidth so users aren't slowed down during transmission of data. The fact that PPTP can support so many forms of security means that it is a very secure form of transmission. The fact that PPTP uses TCP is an advantage due to the fact that TCP allows for the retransmission of lost data.

disadvantages

The disadvantages of PPTP are that it doesn’t encrypt the control message for a transmission session so this means that the connection is susceptible to attack . Due the lack of security PPTP is the weakest VPN protocol. Although PPTP is the most user friendly and cheap to use. the biggest disadvantage is the fact that data encryption only begins after the computers have been through the authentication process and have made the point-to-point connection. It also only requires user-level authentication.

Layer 2 tunneling protocol (L2TP)

Layer 2 Tunneling Protocol (L2TP) is an extension of PPP, it allows ISPs to operate VPNs .It is a combination of PPTP and Layer 2 forwarding developed by Cisco. L2TP does not provide any encryption on its own. It uses the same authentication protocols as PPTP and uses two layers of encapsulation. The first layer is an IP datagram like PPTP and the second is a User Datagram protocol (UDP). Then Internet Protocol Security (IPSec) is used to encapsulate the security payload. The encryption that L2TP uses id encryption keys using Data Encryption Standard and Triple DES or IPSec.

How it works

http://www.interpeak.com/images/products/l2tp.gif (Anon., n.d.)

L2TP works by creating a tunnel between LAC and LNS and allowing a PPP packets to be encapsulated and then transported over the internet. When an end user initiates a PPP connection to a ISP the LAC accepts the connection and creates the link. The connection will be authenticated and then given access if the user allows it. The tunnel is then assigned and a request is made to the LNS which will decide if the connection can be made. When the connection is allowed a virtual PPP creates and links layer frames which can then be transported over the tunnel.

Advantages

L2TP is a multiprotocol so can transport IP,IPX, and apple talk over PPP. It provides excellent and efficient connectivity and is cost effective as it doesn’t have high overhead costs after it is installed.L2TP encrypts the also encrypts the authentication process which improves security, by making it harder for someone trying to intercept the transmission and steal the data. L2TP also prevents data from being changed while being transported between the endpoints. L2TP's use of UDP to encapsulate data makes it quicker and easier to configure the firewall.

Disadvantages

L2TP's security can be weak as it only has simple control of the connection and tunnel authentication. To issue computer certificates L2TP needs to use a certificate infrastructure. It also must have either a digital certificate or shared key before the data is transported. The main disadvantage of L2TP is that it has high overhead load on the network as it has extra security.

Secure Socket tunneling protocol (SSTP)

Secure socket tunneling protocol (SSTP) is an application layer tunneling protocol. It initiates the transport of data between two programs using synchronous communication. it allows for many endpoints over a single connection between peer nodes. It is based on SSL and is very similar to it apart from SSTP being purely a tunneling protocol. SSTP transports L2TP and PPP traffic over a SSL channel, SSL provides security for transport using key-negotiation, encryption and traffic integrity checking. Using SSL means that SSTP can move through most firewalls and proxy servers. It is authenticated while using PPP but can also be authenticated when SSL is in use.

How it works

http://www.purevpn.com/blog/wp-content/uploads/2011/11/sstp-diagram2.png (Anon., n.d.)

SSTP works by encapsulating PPP or L2TP traffic on a HTTPS link. first there must be an internet connection which can be established by the protocol and a TCP connection is made. Then SSL takes place to validate the server certificate, once this is done the connection is made and a HTTPS request is sent over the encrypted SSL link. SSTP control packets are transmitted over the HTTPS link to create a SSTP link on the two machines and then the PPP layer communication starts using SSTP over the HTTPS link on the two machines. The server must then be authenticated and then data can move over the connection.

Advantages

SSTP works in most situations where other connections would be blocked. Using SSL and the way the packets are made and transported over SSTP means that data can pass through most firewalls and proxy servers. It is said to have the best security of a tunneling protocol due to its authentication certificates it uses, the fact it uses SSL and its encryptions. It is very hard to identify SSTP tunnel and so it is difficult to restrict or block the connection.

Disadvantages

SSTP only works on Windows vista and Windows 7, so isn't available for Mac OS or Linux. Due to the fact that clients would see it as very secure people may become forgetful when remotely accessing the server from a public network and so usernames and passwords can be intercepted. It uses TCP so isn't suitable for VoIP, It has low data speed and stability.

Point-to-point Protocol (PPP)

PPP is used in all three of the protocols described above. The PPP packets are encapsulated by the protocols and when a connection is made the packets are sent over the tunneling link which has been encrypted and authenticated by such protocols as CHAP and key negotiation depending on which tunneling protocol is used.

Point-to-Point Protocol (PPP) 'was designed to transport multi-protocol packets between two peers connected by simple links' (Anon., n.d.) PPTP, L2TP and SSTP are extensions of this they take the 'simple link' and enhance the security of PPP. Tunneling protocols also allow PPP to send incompatible payloads over the delivery network.

challenge handshake authentication Protocol(CHAP)

Challenge Handshake Authentication Protocol (CHAP) is used by all three protocols described above. It is used to authenticate the link before the data packets are sent between the two endpoints.

CHAP protects against reply attacks the link by using a variable challenge value and an incrementally changing identifier. It is used in PPP to check the identity of remote clients by using a three way handshake, this happens in all three tunneling protocols when establishing the link.

Conclusion

To conclude L2TP is the best tunneling protocol compared with PPTP and SSTP. PPTP was developed by Microsoft where as L2TP has the features of PPTP combined with Layer 2 Forwarding which makes it faster to transport UDP while still maintaining PPTP's control and data channels. It is more secure than PPTP as it must have certificates compared with PPTP. Even though PPTP is easier to setup and use the security of L2tp makes it a better choice. The way that L2TP transports both control and data streams together, where as PPTP transports them separately so is slower. SSTP's encryption is more extensive than both L2TP and SSTP this may be seen as an advantage as it has a higher level of security but it makes SSTP it overly complicated where as L2TP has a high level of security but is still easier to use than SSTP. L2TP is also faster than SSTP as SSTP has low data speed and stability. L2TP is compatible with Windows XP, Vista, 7, Mac OS X and android where as SSTP is only compatible with Windows 7.