Network Security is one of the most important topic asked during an interview. In most of recruitment process of network related companies like Cisco, Red Hat etc, candidates have to face lot of questions from the network security in written test as well as in the interview process. Basically network security is meant for the policies and provisions adopted by the administrator for preventing unauthorized access. In this content we have interview questions related to network security with their explanations. Most of the questions has been taken from previous recruitment process. Still if it contains any error please do let us know. You can give your valuable feedback through the comment section, any type of suggestions will be highly appreciated.
1. Define security attack, security mechanism and security services.
The followings says about the security attack,security mechanism and security services
- Security attack : Actions that compromises the security about information owned by an organization.
- Security mechanism : Mechanisms which is designed for detecting, preventing or recovering from a security attack.
- Security services : Services which enhances the security of the data processing systems and transfer of the information an organization.
2. What is security association?
Security association is a single way relationship between a receiver and a sender that provides security services to the traffic on it.
3. Why do we need an anti replay service?
Anti replay service is needed for avoiding the duplicate packets which causes disruption in the service.
4. What is the need of padding in Encapsulating Security Payload (ESP)?
The need of pf padding in encapsulating security payload(ESP) are
- If an encryption algorithm requires the plain text to be a multiple of some number of bytes, the padding field is used to expand the plain text to the required length.
- ESP format requires that the pad length and the next header fields be right aligned within a 32-bit word. The padding field is used to assure this alignment.
- Additional padding may be added to provide partial traffic flow secretly by concealing the real length of the payload.
5. Define firewall.
Firewall is the in which protects the environment network from web based attacks and to provide a single choke point where security and audit can be imposed.
6. What are the design goals of the firewall.
The design goals of the firewall is
- All traffic from inner side to outer side, and vice verca, must pass through the firewall.
- As said by the local security policy, only authorized traffic, , can be said to allow.
- It is immune to penetration.
7. Define Trojan horse attack.
The Trojan horse attack begins with a hostile user whose name X, gain Legitimate allow for access into the system and installs both the a private file and trojan horse program to be used in the attack as a ‘backpacket’. X gives read / write permission to itself and gives Y(authorized user) only write permission. X now indicates Y to invoke trojan horse program, by advertising it as a useful utility.When the program detects that Y executed it, it reads the sensitive character string from file of Y and copies it into X’s back pocket file.
8. Outline the 2 rules for multi-level security.
The 2- rules for multi-level security
- An issue will solely browse on object of less or equal security level. this can be named as easy security property.
- An issue will solely write into AN object of bigger or equal security level. this can be named as ‘*’ property
9. Define transport and tunnel mode.
For defining transport and tunnel mode we can say
- Transport mode provides protection primarily for higher layer protocols. Transport mode protection extends to the payload of an IP packet. Transport mode is employed for end-to-end communication between 2 hosts.
- Tunnel mode provides protection to the packet which is finished. The entire packet (original packet) and security fields is treated because the payload of recent outer IP packet with a brand new outer IP header. The packet travels through a tunnel from one purpose of an IP network to another.
10. What’s the necessity of public ring and personal key ring?
<p”>The necessity of public ring and personal key ring is Public ring is one in all the info structures that is employed to store the public keys of the opposite participants Private ring could be a organisation that is employed to store the general public and the non-public keys of the owner alone.
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