Can you explain the concept of CIDR

CIDR (Classless Inter-Domain Routing) was introduced in 1993 (RCF 1517) replacing the previous generation of IP address syntax – classful networks. CIDR allowed for more efficient use of IPv4 address space and prefix aggregation, known as route summarization or supernetting. CIDR introduction allowed for: -More efficient use of IPv4 address space -Prefix aggregation, which reduced [...]

What is subnetting

When we Subnet a network, we basically split it into smaller networks. For example, when a set of IP Addresses is given to a company, e.g 254 they might want to “break” (the correct term is “partition”) that one network into smaller ones, one for each department. This way, their Technical department and Management department [...]

Can you explain the role of each layer in OSI model

Layer 7— The application layer: This is the layer at which communication partners are identified, quality of service is identified, user authentication and privacy are considered, and any constraints on data syntax are identified. (This layer is not the application itself, although some applications may perform application layer functions). It represents the services that directly [...]

What do the following statements in an extended access list accomplish?

What do the following statements in an extended access list accomplish? access-list 101 deny TCP 172.16.4.0 0.0.0.255 172.16.3.0 0.0.0.255 eq 21 access-list 101 deny TCP 172.16.4.0 0.0.0.255 172.16.3.0 0.0.0.255 eq 20 access-list 101 permit TCP 172.16.4.0 0.0.0.255 0.0.0.0 255.255.255.255 A. This will block ftp traffic. B. This will block http traffic. C. This will permit [...]

Cisco routers use wildcard masking to identify how to check or ignore corresponding IP address bits. What does setting a wildcard mask bit to 0 cause the router to do?

Cisco routers use wildcard masking to identify how to check or ignore corresponding IP address bits. What does setting a wildcard mask bit to 0 cause the router to do? A. It tells the router to check the corresponding bit value. B. It tells the router to ignore the corresponding bit value. C. It tells [...]

Can you define in short what VPN is?

Can you define in short what VPN is? ->A Virtual Private Network (VPN) is a network technology that creates a secure network connection over a public network such as the Internet or a private network owned by a service provider. Large corporations, educational institutions, and government agencies use VPN technology to enable remote users to [...]

Can you explain what IPSec is

Can you explain what IPSec is ->ipsec is a suite of protocols which ensure the following: 1-confidentiality of data 2-integrity of data 3-anti-replay of data 4-non-repudiation contains the main cryptographic algorithms used in securing traffic between two networks over an un trusted network