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Open Shortest Path First (OSPF) is a router protocol used to find the best path for packets as they pass through a set of connected networks.This protocol is designated by the Internet Engineering Task Force (IETF) one of the Interior Gateway Protocols (IGPs) aimed at traffic moving around within a larger autonomous system network like a single enterprise's network, which may in turn be made up of many separate local area networks linked through routers.ExplanationArea 1 Border router Area 0 Backbone zone Border router Area 2 OSPF.OSPF protocol is called a link state routing protocol, which maintains link state databases. ... Read More
To filter on the basis of sum of columns, we use the loc() method. Here, in our example, we sum the marks of each student to get the student column with marks above 400 i.e. 80%.At first, create a DataFrame with student records. We have marks records of 3 students i.e 3 columns −dataFrame = pd.DataFrame({ 'Jacob_Marks': [95, 90, 75, 85, 88], 'Ted_Marks': [60, 50, 65, 85, 70], 'Jamie_Marks': [77, 76, 65, 45, 50]}) Filtering on the basis of columns. Fetching student with total marks above 400 −dataFrame = dataFrame.loc[:, dataFrame.sum(axis=0) > 400]ExampleFollowing is the complete ... Read More
Internet Control Message Protocol (ICMP) shares error reporting and device status messages which can be further divided into specific message types with their codes.These message types can be divided into two categories −Error Reporting MessagesQuery MessagesThese message types are shown below −Error Reporting MessagesThese are messages which are sent when an error is reported by ICMP protocol.Some of common messages under this category are as follows:Destination Unreachable (Type 3)One of the most common error reporting messages occurs when the router is unable to locate the path of the packet where it is needed to be delivered and in this case ... Read More
There are three security issues that are applicable to the IP protocol −Packet SniffingPacket ModificationIP SpoofingLet us discuss each issue in detail.Packet SniffingA guest may intercept an IP packet and create a copy of it.The packet sniffing is generally a passive attack, where the attacker does not change the contents of the packet.Packet sniffing attack is difficult to detect because here the sender and receiver doesn’t know that the packet has been copied.Even though the packet sniffing cannot be stopped, the encryption of the packet can make the attacker’s effort useless. Still the attackers may sniff the packet, but the ... Read More
The Internet Protocol version 4 (IPv4) is called the fourth version in the development of the Internet Protocol. Its address is a 32-bit address which uniquely defines the connection that means here each address defines one, and only one, connection to the Internet.If a device has two connections to the Internet, via two networks, then we call it has two IPv4 addresses.IPv4 addresses are universal in a sense where the addressing system must be accepted by any host that wants to be connected to the Internet.Ipv4 address notationThere are three notations to show an IPv4 address which are as follows ... Read More
To select first periods of time series based on a date offset, use the first() method. At first, set the date index with periods and freq parameters. Freq is for frequency −i = pd.date_range('2021-07-15', periods=5, freq='3D')Now, create a DataFrame with above index −dataFrame = pd.DataFrame({'k': [1, 2, 3, 4, 5]}, index=i) Fetch rows from first 4 days i.e. 4D −dataFrame.first('4D')ExampleFollowing is the complete code − import pandas as pd # date index set with 5 periods and frequency of 3 days i = pd.date_range('2021-07-15', periods=5, freq='3D') # creating DataFrame with above index dataFrame = pd.DataFrame({'k': [1, 2, 3, ... Read More
Let us understand the concept of flow control and congestion control.Flow controlIt is handled by a receiving side and it safeguards that a sender can only send something that a receiver can control or handle.Flow control handles a mechanism available to safeguard that communication flows smoothly.For example, a situation where somebody has a quick fiber connection could be sending on something or dial up similar. A sender could have the capability to send packets quickly, however that can be useless to a receiver on dialup. Thus they require a method to throttle the sending side.The issues related to flow control ... Read More
The Congestion at the network layer came across two issues which are throughput and delay.Based on DelayWhen compared to capacity of the network, if load is less, the delay is minimum.Here the minimum delay is composed of propagation delay and processing delay and both are negligible.Therefore, when load reaches the network capacity, the delay increases because we must add the queuing delay to the total delay.When the load is greater than the capacity the delay becomes infinite.Based on ThroughoutWhen load is below the capacity of the network, the throughput increases proportional to the load.After the load reaches the capacity, we ... Read More
The performance of a network can be measured in terms of Delay, Throughput and Packet loss.Let us try to understand the concept of Delay.DelayA packet from its source to its destination, encounters delays. The delays in a network can be divided into four types as follows −Transmission delayTransmission delay is the amount of time taken by the router to transfer the packet to the outgoing link is called transmission delay.For example, assume that you have 100 kb of data. For this data, you have to keep on this outgoing link and this is known as Transmission delay.Suppose you are vacating ... Read More
To merge Pandas DataFrame, use the merge() function. In that, you can set the parameter indicator to True or False. If you want to check which dataframe has a specific record, then use −indicator= TrueAs shown above, using above parameter as True, adds a column to the output DataFrame called “_merge”.At first, let us import the pandas library with an alias −import pandas as pd Let us create DataFrame1 −dataFrame1 = pd.DataFrame( { "Car": ['BMW', 'Lexus', 'Audi', 'Mustang', 'Bentley', 'Jaguar'], "Units": [100, 150, 110, 80, ... Read More