How are routing neighbours discovered in BGP

A BGP-speaking router does not discover another BGP-speaking device automatically. A network administrator usually manually configures the relationships between BGP-speaking routers. A BGP neighbor device is a BGP-speaking router that has an active TCP connection to another BGP-speaking device. This relationship between BGP devices is often referred to as a peer instead of neighbor because [...]

What is the concept of NLRI

BGP was designed to carry only unicast IPv4 routing information. BGP configuration used the Network Layer Reachability Information (NLRI) format CLI in Cisco IOS software. The NLRI format offers only limited support for multicast routing information and does not support multiple network layer protocols.

What are BGP path attribute

-Prefer the path with the highest WEIGHT. Note: WEIGHT is a Cisco-specific parameter. It is local to the router on which it is configured. -Prefer the path with the highest LOCAL_PREF. Note: A path without LOCAL_PREF is considered to have had the value set with the bgp default local-preferencecommand, or to have a value of [...]

Can you explain different OSPF packet types

Hello-Used to discover and maintain neighbours. Database Description-Used to form adjacencies. The router summarises all its linkstate advertisements and passes this information, via database description packets to the router it is forming an adjacency with Link State Request After the database description packets have been exchanged with a neighbour, the router may detect link state advertisements it requires to update [...]

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 [...]