The unique number will be generated by MD5, if it is tamped with someone, the value will be changed so you know you are tampered
(a) OSPF has two primary characteristics. The first is that the protocol is open, which means that its specification is in the public domain. The OSPF specification is published as Request For Comments (RFC) 1247.
The second principal characteristic is that OSPF is based on the SPF algorithm, which sometimes is referred to as the Dijkstra algorithm, named for the person credited with its creation.
(b)OSPF is a link-state routing protocol that calls for the sending of link-state advertisements (LSAs) to all other routers within the same hierarchical area. Information on attached interfaces, metrics used, and other variables is included in OSPF LSAs. As OSPF routers accumulate link-state information, they use the SPF algorithm to calculate the shortest path to each node.
Ospf: Open Shortest Path First.
It Uses SPF(Dijkstra) algorithm and selects the Loopfree path. It is a purely classless Routing protocol(ie sends mask along with the ip address)
It supports SLSM, VLSM, Discontinuous Networks. and the hope count is Unlimited. It is Having Complex Configuration Including Area, Process id, Wild card mask. The metric used is bandwidth(10raise to8/Bandwidth). Administrative Distance is 110
RSA is based upon public key/private key concept. For authentication one can encrypt the hash (MD5/SHA) of the data with his private key. This is known as digital signature. And secrecy is achieved by encrypting the data with the public key of the target user. Generally we dont use RSA for encryption because of key size (1024 bits). Rather a symmetric session key (128/256 bit) is established between communicating parties and is used for encryption.
RSA -- Authentication can be achieved by using nonce value (prime number).
Eg: A wanna communicate with B
The val An1 is encrypted with private key of A and then with pub key of B. so B can decrypt it and then B should send back the An1 to A stating it none other than B
Secrecy is also maintained because they use their own private keys for decryption
DAS (discretionary access control) is used by itself according to it it is access and comtrolled while mas it has to be compulsory give the access controll.
MAC is designed and enforced in the initial stages and can not be changed by entity; from a laymen angle: OS writing to BIOS is not allowed.
DAC is designed in such a way that access shall be granted based on the discretion; ex. database table access.
Classfull routing protocol is a routing protocol that strictly. follows the classfull IP like IGRP,RIP
Classless Routing A scheme which allocates blocks of Internet addresses in a way that allows summarisation into a smaller number of routing table entries.
classful routing:in this routing only ip addresses are used..subnet mask is not used.due to which it does not support subnetting and vlsm
classless uses subnet mask alos...due to which subnetting and vlsm is possible in this case
Rip v1 is classfull routing protcol
Rip v2 is classless routing protocol
multicasting is sending data(packets) to more than one computers but not all on that network