Lab today is about the security network. Network security involves all activities that organizations, enterprises, and institutions undertake to protect value and ongoing usability of assets and the integrity of operations. Firewall, Intrusion detection system (IDS), Intrusion Prevention system(IPS), Honeypot and Kerberos is among application introduce to protect network services on network from being attack by hackers. On the other hand, IPSec is a set of protocols developed by the IETF to support secure exchange of packets at the IP layer. IPsec has been deployed widely to implement Virtual Private Networks (VPNs).
In this practical lab, the task 1 is capturing File Transfer Protocol (FTP) Username and password. FTP and Telnet is not secure because send username and password in clear text. Using Wireshark can sniff all the packet transfer during session. Before doing this task, we have to make sure that Wireshark installed in PC. This activity required 2 Win Server 2003 Virtual Machine.
Task 2 is using IPSec to secure FTP Transaction. IPSec is one of the solutions to safeguard the transmission of data over FTP from being seen by an unauthorized user. IPSec will encrypt the data sent using normal FTP connection. Thus only the authorized party can see the content. After setting all configuration, we are try to login according to task 1. We found that username and password cannot be display in task 2.
As a conclusion, we can identify the vulnerabilities of FTP by using Wireshark and enabling IPSec for securing FTP session. Security for a network is very important to prevent unauthorized user get the data or modify it.
A computer network is a system in which computers are connected to share information and resources. The network resources are computers, operating system, programs, processes and people.Node, host, link, and topology are basic terminology. Computer network topologies can be categorized by bus, star, ring, mesh and tree. The Open System Interconnection (OSI) model defines a networking framework for implementing protocols in seven layers.
The advantages of computing network are as below:-
·File Sharing: allows file sharing and remote file access. It saves the time which is wasted in copying a file from one system to another, by using a storage device.
·Resource Sharing: computers which are connected through a network can share resources as hard drives, printers, scanners etc with each other. Besides that, it reduces maintenance and storage costs.
·Increased Cost Efficiency: software can be stored or installed on a system or a server and can be used by the different workstations.
·Expandability: System is easily expanded by adding new nodes.
The disadvantages of computing network are as below:-
·Information Security: if a computer is connected to a network, it is much easier to send any secret information stored on that computer to some other computer on the network.
·Complexity: a network may combine two or more systems with dissimilar operating systems with different mechanisms for interhost connection. Complexity of this nature makes the certification process extremely difficult.
·Unknown perimeter: one host may be a node on two or more different networks.
There are many threats in networks which are security exposures, impersonating,eavesdropping, denial of service, packet replay, and packet modification. Network security can be control by using encryption, strong authentication, and Kerberos. Firewall is also a network security control. In network applications, encryption can be applied either between two hosts (called link encryption) or between two applications (called end-to-end encryption). Link encryption can be used to give a network's users the sense that they are on a private network, even when it is part of a public network. For this reason, the approach is called a virtual private network (or VPN).SSH (secure shell) is a pair of protocols (versions 1 and 2), originally defined for Unix but also available under Windows 2000, that provides an authenticated and encrypted path to the shell or operating system command interpreter. The SSL (Secure Sockets Layer) protocol was originally designed by Netscape to protect communication between a web browser and server. It is also known now as TLS, for transport layer security. IPSec is mandatory for IPv6 but optional for IPv4. IPSec is used to address serious security requirements which are spoofing, eavesdropping and session hijacking.Strong authentication is a form of computer security in which the identities of networked users, clients and servers are verified without transmitting passwords over the network. Kerberos is a network authentication protocol. It is designed to provide strong authentication for client/server applications by using secret-key cryptography. A free implementation of this protocol is available from the Massachusetts Institute of Technology. Kerberos is available in many commercial products as well.
In last, a firewall is a secure and trusted machine that sits between a private network and a public network. The firewall machine is configured with a set of rules that determine which network traffic will be allowed to pass and which will be blocked or refused. Several types of firewall techniques exist:
Packet filtering: The system examines each packet entering or leaving the network and accepts or rejects it based on user-defined rules. Packet filtering is fairly effective and transparent to users, but it is difficult to configure. In addition, it is susceptible to IP spoofing.
Circuit-level gateway implementation: This process applies security mechanisms when a TCP or UDP connection is established. Once the connection has been made, packets can flow between the hosts without further checking.
Acting as a proxy server: A proxy server is a type of gateway that hides the true network address of the computer connecting through it. A proxy server connects to the Internet, makes the requests for pages, connections to servers, and receives the data on behalf of the computer behind it.
