Interview Questions.

Question 1. What Is Firewall?

Answer :

A firewall is a hardware or software program established to offer protection to the non-public networks connected to the internet. They may be applied in each hardware and A firewall is a hardware or software program set up to provide security to the non-public networks linked to the net. They may be carried out in both hardware and software program, or a combination of each. All statistics coming into or leaving the Intranet passes thru the firewall which permits handiest the data assembly the directors’ rules to pass through it.Software program, or a aggregate of each. All facts entering or leaving the Intranet passes thru the firewall which lets in handiest the statistics assembly the administrators’ policies to pass through it.

Question 2. What Is Log Processing?

Answer :

How audit logs are processed, looked for key occasions, or summarized.

Network Security Interview Questions
Question 3. Define Digital Signatures?

Answer :

Digital signature is an attachment to an electronic message used for security purpose. It is used to affirm the authenticity of the sender.

Question 4. What Is Access Control Lists?

Answer :

Rules for packet filters (typically routers) that outline which packets to pass and which to dam.

Network Security Tutorial
Question 5. What Are The Types Of Firewalls?

Answer :

Packet Filtering Firewall: This kind of Firewall detects packets and block unnecessary packets and makes community traffic launch.

Screening Router Firewalls: It's a software base firewall available in Router gives simplest light filtering.

Computer-based Firewall: It's a firewall stored in server with an current Operating System like Windows and UNIX.

Hardware base Firewall: Its device like field permits robust security from public community. Mostly utilized by big networks.

Proxy Server: Proxy server lets in all clients to access Internet with exceptional get right of entry to limits. Proxy server has its own firewall which filters the all packet from net server.

Internet Security Interview Questions
Question 6. What Is Ip Spoofing?

Answer :

An attack wherein a gadget tries to illicitly impersonate another gadget by using the use of its IP network deal with.

In pc networking, the time period IP cope with spoofing or IP spoofing refers back to the advent of Internet Protocol (IP) packets with a cast supply IP deal with, called spoofing, with the motive of concealing the identification of the sender or impersonating another computing device.

Question 7. What Is Defense In Depth?

Answer :

The protection approach wherein each machine at the community is secured to the finest possible diploma. May be used at the side of firewalls.

Internet Security Tutorial Computer Network Security Interview Questions
Question 8. What Is The Public Key Encryption?

Answer :

Public key encryption use public and private key for encryption and decryption. In this mechanism, public key is used to encrypt messages and simplest the corresponding personal key may be used to decrypt them. To encrypt a message, a sender has to know recipient’s public key.

Question nine. What Is Worm?

Answer :

A standalone software that, when run, copies itself from one host to any other, and then runs itself on each newly inflamed host. The extensively suggested 'Internet Virus' of 1988 become not a deadly disease in any respect, however sincerely a worm.

Veritas Volume Manager (VVM or VxVM) Interview Questions
Question 10. Explain Abuse Of Privilege?

Answer :

When a user plays an action that they ought to now not have, according to organizational policy or regulation.

Question eleven. What Is Data Encryption?

Answer :

Data encryption ensures facts safety and very essential for personal or critical data. It guard information from being examine, altered or solid even as transmission.

Spotfire (TIBCO) Interview Questions
Question 12. What Is Uthentication?

Answer :

The technique of figuring out the identity of a user that is attempting to get admission to a gadget.
Authentication is a system that can verify computer identity(user call and pass and so on)

Network Security Interview Questions
Question thirteen. What Is Least Privilege?

Answer :

Designing operational components of a gadget to operate with a minimum amount of gadget privilege. This reduces the authorization stage at which diverse actions are executed and decreases the danger that a process or person with high privileges may be brought about to carry out unauthorized interest resulting in a safety breach.

Question 14. What Is Authentication Token?

Answer :

A portable device used for authenticating a person. Authentication tokens function via undertaking/reaction, time-primarily based code sequences, or different techniques. This can also include paper-primarily based lists of 1-time passwords.

Question 15. What Is Tunneling Router?

Answer :

A router or machine able to routing site visitors by encrypting it and encapsulating it for transmission across an untrusted community, for eventual de-encapsulation and decryption.

Cisco Unified Computing System Interview Questions
Question sixteen. What Is Cryptographic Checksum?

Answer :

A one-way characteristic carried out to a record to provide a unique ``fingerprint'' of the record for later reference. Checksum structures are a primary manner of detecting filesystem tampering on Unix.

Question 17. Explain You Are Currently Designing Your Own Desktop Publishing Application, As You Have Not Found Any That?

Answer :

You are presently designing your very own Desktop Publishing software, as you haven't located any that do exactly what you need with present applications. As a part of the layout you're the use of a Controller to which you ship all GUI requests. Not all objects can system the identical instructions. For example you could?T pick the spell test device while an photo has the point of interest. To forestall any possible errors you would like to filter a number of the messages as they may be handed from these objects to.

Virtual Private Network (VPN) Interview Questions
Question 18. What Is Ip Splicing/hijacking?

Answer :

An attack whereby an lively, established, consultation is intercepted and co-opted with the aid of the attacker. IP Splicing attacks might also occur after an authentication has been made, permitting the attacker to anticipate the function of an already authorized consumer. Primary protections in opposition to IP Splicing depend upon encryption on the consultation or network layer.

Internet Security Interview Questions
Question 19. What Is Screened Host?

Answer :

A host on a network at the back of a screening router. The diploma to which a screened host may be accessed relies upon at the screening rules in the router.

Question 20. What Is Dns Spoofing?

Answer :

Assuming the DNS call of any other system by using either corrupting the name service cache of a sufferer gadget, or by using compromising a site name server for a valid domain.

CheckPoint Firewall Interview Questions
Question 21. What Is Bastion Host?

Answer :

A system that has been hardened to resist attack, and that is mounted on a community in the sort of way that it is predicted to probably come under assault. Bastion hosts are often components of firewalls, or may be ``out of doors'' net servers or public get right of entry to systems. Generally, a bastion host is going for walks a few shape of fashionable motive operating machine (e.G., Unix, VMS, NT, and so on.) in place of a ROM-primarily based or firmware operating gadget.

Question 22. What Is Screened Subnet?

Answer :

A subnet behind a screening router. The degree to which the subnet can be accessed depends at the screening rules inside the router.

Question 23. What Is Dual Homed Gateway?

Answer :

A dual homed gateway is a gadget that has  or extra network interfaces, every of that's linked to a distinct network. In firewall configurations, a dual homed gateway typically acts to dam or filter out a few or all the site visitors looking to bypass among the networks.

Cisco Network Engineer Interview Questions
Question 24. What Is Log Retention?

Answer :

How long audit logs are retained and maintained.

Computer Network Security Interview Questions
Question 25. What Is Perimeter-primarily based Security?

Answer :

The technique of securing a community by using controlling access to all access and go out factors of the community.

Question 26. Which Feature On A Firewall Can Be Used For Mitigating Ip Spoofing Attacks?

Answer :

Access manipulate list may be used for the purpose.

Cisco Asa Firewall Interview Questions
Question 27. What Type Of Firewall Can Be Used To Block A Web Security Threat?

Answer :

A web utility firewall or a layer 7 firewall may be used for the motive.

Veritas Volume Manager (VVM or VxVM) Interview Questions
Question 28. Which Fields In A Packet Does A Network Layer Firewall Look Into For Making Decisions?

Answer :

IP and shipping layer headers for facts related to supply and vacation spot IP addresses, port numbers and so on.

Question 29. Which Is The Main Field In An Ip Header , Which Is Modified By A Nat Firewall?

Answer :

The supply IP cope with in the IP header.

Question 30. Which Feature On A Cisco Firewall Can Be Used For Protection Against Tcp Syn Flood Attacks?

Answer :

TCP intercept function.

Question 31. What Is The Difference Between Gateway And Firewall?

Answer :

A Gateway joins  networks together and a community firewall protects a network towards unauthorized incoming or outgoing access. Network firewalls may be hardware gadgets or software programs.

Question 32. What Is The Difference Between Stateful & Stateless Firewall?

Answer :

Stateful firewall - A Stateful firewall is privy to the connections that bypass via it. It provides and continues information about customers connections in country table, referred to as a connection table. It than uses this connection table to implement the safety rules for customers connections. Example of stateful firewall are PIX, ASA, Checkpoint.

Stateless firewall - (Packet Filtering) Stateless firewalls however, does no longer examine the country of connections but just on the packets themselves. Example of a packet filtering firewall is the Extended Access Control Lists on Cisco IOS Routers.

Question 33. What Information Does Stateful Firewall Maintains?

Answer :

Stateful firewall maintains following records in its State desk:-

Source IP deal with.
Destination IP cope with.
IP protocol like TCP, UDP.
IP protocol statistics which includes TCP/UDP Port Numbers, TCP Sequence Numbers, and TCP Flags.
Spotfire (TIBCO) Interview Questions
Question 34. Firewalls Works At Which Layers?

Answer :

Firewalls work at layer 3, four & 7.

Question 35. Explain Dmz (demilitarized Zone) Server?

Answer :

If we want a few network resources such as a Web server or FTP server to be available to out of doors users we region those resources on a separate community behind the firewall called a demilitarized zone (DMZ). The firewall allows limited access to the DMZ, however due to the fact the DMZ only consists of the public servers, an assault there best influences the servers and does not have an effect on the internal network.

Question 36. How Asa Works In Reference To Traceroute?

Answer :

ASA does now not decrement the TTL value in traceroute because it does not want to provide its information to others for security motive. It forwards it with out decrementing the TTL Value.

Cisco Unified Computing System Interview Questions
Question 37. What If We Apply Acl As Global In Asa?

Answer :

It might be carried out on all interfaces closer to inbound. Global option is only in ASA 8.4 now not in ASA eight.2

Question 38. What Are The Different Types Of Acl In Firewall?

Answer :

1.Standard ACL
2.Extended ACL
3.Ethertype ACL (Transparent Firewall)
4.Webtype ACL (SSL VPN)

Question 39. What Is The Difference In Acl On Asa Than On Router?

Answer :

In router, if we delete one access-manage access complete ACL might be deleted. In ASA, if we are able to delete one access-manipulate entry entire ACL will no longer be deleted.

Question forty. What Is The Need Of Transparent Firewall?

Answer :

If we need to install a brand new firewall into an present community it is able to be a complicated procedure due to numerous troubles like IP cope with reconfiguration, network topology modifications, cutting-edge firewall and many others. We can without problems insert a obvious firewall in an present section and control site visitors between two facets without having to readdress or reconfigure the gadgets.

Virtual Private Network (VPN) Interview Questions
Question forty one. What Is Tranparent Firewall?

Answer :

In Transparent Mode, ASA acts as a Layer 2 tool like a bridge or switch and forwards Ethernet frames primarily based on vacation spot MAC-deal with.

Question 42. Explain Ether-kind Acl?

Answer :

In Transparent mode, unlike TCP/IP visitors for which safety degrees are used to allow or deny visitors all non-IP traffic is denied by way of default. We create Ether-Type ACL to permit NON-IP visitors. We can manage site visitors like BPDU, IPX and so forth with Ether-Type ACL.

CheckPoint Firewall Interview Questions
Question forty three. Explain Failover?

Answer :

Failover is a cisco proprietary characteristic. It is used to offer redundancy. It requires  equal ASAs to be linked to each other thru a devoted failover hyperlink. Health of lively interfaces and gadgets are monitored to decide if failover has happened or no longer.

Question forty four. What Is The Difference Between Stateful Failover And Stateless Failover?

Answer :

Stateless Failover: When failover occurs all energetic connections are dropped. Clients want to re-establish connections when the new active unit takes over.

Stateful Failover: The lively unit continually passes per-connection state data to the standby unit. After a failover happens, the same connection information is available at the new active unit. Clients aren't required to reconnect to preserve the same conversation consultation.

Question 45. What Information Active Unit Passes To The Standby Unit In Stateful Failover?

Answer :

NAT translation desk, TCP connection states, The ARP desk, The Layer 2 bridge table (when strolling in obvious firewall mode), ICMP connection state and so on.

Question 46. What Are The Failover Requirements Between Two Devices?

Answer :

Hardware Requirements: The  units in a failover configuration ought to be the equal version, need to have identical number and kinds of interfaces.

Software Requirements: The  units in a failover configuration have to be within the same working modes (routed or transparent single or a couple of context). They ought to have the equal software model.

Question forty seven. Explain Active/standby Failover?

Answer :

In Active/Standby Failover, one unit is the energetic unit which passes traffic. The standby unit does not actively bypass visitors. When Failover occurs, the active unit fails over to the standby unit, which then becomes energetic. We can use Active/Standby Failover for ASAs in both single or multiple context mode.

Question 48. Explain Security Context?

Answer :

We can partition a Single ASA into a couple of virtual devices, known as Security Contexts. Each Context acts as an impartial device, with its very own protection policy, interfaces, and administrators. Multiple contexts are just like having a couple of standalone devices.

Question forty nine. What Features Are Supported In Multiple Context Mode?

Answer :

Routing tables, Firewall features, IPS, and Management.

Question 50. What Features Are Not Supported In Multiple Context Mode?

Answer :

VPN and Dynamic Routing Protocols.