tag:blogger.com,1999:blog-88171731920138798122026-08-09T13:38:07.459+05:30Thoughts on managing technology & people. I write about personal challenges faced & discuss latest stories from tech sectorAnadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.comBlogger47125tag:blogger.com,1999:blog-8817173192013879812.post-74197531495756531182020-03-27T13:15:00.002+05:302020-03-27T13:58:25.681+05:30

[Disclaimer: Had drafted this post couple of years back, and somehow hadnt published it. Some of the principles and observations are still relevant though] Smartphones have captured the imagination of India. According to IDC, it was one of the fastest growing market witnessing a 14% increase in shipments to 124 million units in 2017 alone. The opportunity has obviously meant an intense

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com0tag:blogger.com,1999:blog-8817173192013879812.post-31100955848439342712016-08-21T01:18:00.002+05:302018-04-08T14:23:19.740+05:30

The motivation to write this article came when I came across Section 197 Companies Act India (and learn data scraping using python! :P ) For the complete technicalities you may read this article. In a nutshell, it specifies a limit to what the Board of Directors and managers can be paid by a public company. And on top of that, this information has to be disclosed in the annual report. Yes, a

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com0tag:blogger.com,1999:blog-8817173192013879812.post-7793628638885783042016-03-13T23:49:00.000+05:302016-03-13T23:49:23.747+05:30

Before I delve into the anti DDoS methodologies involved let me explain what a DdoS is and how it can impact you-the customer. Denial Of Service (DoS) DoS stands for Denial of Service which involves bad guys (known as hackers) sending so much garbage data directing to  the customer's site that it's performance starts getting affected. In other words a hacker sends so much garbage requests

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com1tag:blogger.com,1999:blog-8817173192013879812.post-80497970548897178592015-04-20T12:41:00.001+05:302015-04-20T12:44:12.501+05:30

In networking and system administration redundancy and high uptime is one of the most important requirements. I have already covered about SRX (Juniper's firewall) redundancy in a previous article(link at the end). This post helps to configure redundancy for a very important piece of network equipment- switch. Juniper provides an exciting feature called the Virtual Chassis (VC). What is a

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com3tag:blogger.com,1999:blog-8817173192013879812.post-20299927520861789582015-04-09T17:56:00.000+05:302015-04-09T17:56:31.077+05:30

In Juniper SRX High Availability (HA) & clustering: Part 1 I discussed the theory of the key terms and concepts used in configuring reth groups, fab links and clustering in general. In this part we actually dive deep into the actual configuration. The broad steps that will be covered in this part: 1) Setting up control links 2) Setting up fab links 3) Creating a redundancy group 4)

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com0tag:blogger.com,1999:blog-8817173192013879812.post-20739390415103218662014-05-05T20:07:00.001+05:302014-05-06T14:09:11.721+05:30

SRX is an enterprise grade firewall solution build by Juniper, one of the largest network equipment providers. In our organisation we have used SRX extensively as a firewall and IPS device. One of the great features of SRX is the ability to run it in a cluster, working in tandem. High Availability (HA) Failure of devices, links getting damaged or bugs crashing the OS are only a tiny fraction

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com4tag:blogger.com,1999:blog-8817173192013879812.post-80190212473220891972014-03-03T17:47:00.000+05:302014-03-03T17:47:55.043+05:30

What really caught my attention after reading about Kevin Mitnick was how he conducted the TCP blind spoofing attack. It was an attack which required packet crafting and insertion into an already established TCP connection. What is interesting about this attack is that it does not require knowledge about any specific tools but instead relies on the person's knowledge about the protocol. So I

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com2tag:blogger.com,1999:blog-8817173192013879812.post-28855662873409142252014-02-16T00:14:00.000+05:302014-02-16T00:14:11.035+05:30

This is one of the simplest DoS attacks I have ever seen. It is very easy to carry out and it's effects are devastating. It is a little different from normal DoS attacks in the sense that even when the attacker stops the attack the victim machines' resources will not free up! This makes it very lethal. The other point of difference is that it can be carried out only in a LAN environment.

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com1tag:blogger.com,1999:blog-8817173192013879812.post-53555784024002543782013-06-08T10:53:00.002+05:302013-06-08T10:53:46.411+05:30

The last post talked about how to modify incoming traffic. What about outbound traffic? Generally, for an enterprise the outbound traffic will be more than inbound. Situation may arise that one of your multihomed link starts clogging up and you will want to shift some traffic to the other link. Remember, that for inbound traffic you might not have full control over the path which it should

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com2tag:blogger.com,1999:blog-8817173192013879812.post-29050183640884558982013-05-30T20:42:00.002+05:302013-06-07T09:30:47.077+05:30

In network and system architecture in general, it is a fact that things go down. System and processes fail and therefore we must build redundancy. A production network connected to a single link is a catastrophe waiting to happen. If that particular link fails the production network will no longer have access to the Internet and vice versa. This is why it is always recommended to have another

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com4tag:blogger.com,1999:blog-8817173192013879812.post-76013623601589816142013-05-28T16:48:00.000+05:302013-06-08T10:54:22.511+05:30

The previous post (configuring bgp on juniper mx) gave you a brief hint about BGP and how a basic session can be established from a Juniper router. This post will move on further to explain how to override the default policy, which is to receive and export all active BGP routes, and customize the advertisement according to our needs. Suppose you have procured a subnet like 200.200.200.0/23 (

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com4tag:blogger.com,1999:blog-8817173192013879812.post-92021422087263833662013-05-27T02:30:00.000+05:302013-06-08T10:54:36.147+05:30

I have been fortunate to be working on one of the heavy duty routers found in the networking jungle. Juniper is an established and trusted brand among many ISPs and big enterprises. The MX series routers are industry leaders and combine the functionalities of an M series router and EX series switch. But this post will not delve into the product description. This post is more about how to

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com0tag:blogger.com,1999:blog-8817173192013879812.post-53681907326902403042013-03-19T18:28:00.000+05:302013-06-08T18:31:02.850+05:30

By now I have given four interviews involving tricky technical questions from "The difference between a void object and a null object" to "explain how internet works to a layman". I have given two interviews on the phone with contrasting results. The first proper interview that I gave was to Birlasoft for an internship during summer of 2011. I had applied for a software programming and got a

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com2tag:blogger.com,1999:blog-8817173192013879812.post-49459449541378743262012-12-11T10:34:00.003+05:302016-12-07T11:29:02.351+05:30

The last article was about layer 3 switches and how they can be useful in your network. Today I introduce another technology which is introduced in CCNA. Suppose I have  a switch connected to a server by a 1 gbps link. Now suppose two servers want to exchange data at very high speed but are not able to because of the limit on the carrier capacity. What if I could tell the switch to make (

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com5tag:blogger.com,1999:blog-8817173192013879812.post-76404809863687057292012-12-09T14:34:00.000+05:302013-06-08T11:21:34.923+05:30

This is an introductory article to talk about some of the fundamental technologies which will be useful for students of CCNA and CCNP certification exam. Please note that this is not the most comprehensive guide but i hope it will immensely help not only the CCNA/CCNP candidates but network administrators, architects as well. Through this series I will cover interesting topics such as: 1. What

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com4tag:blogger.com,1999:blog-8817173192013879812.post-30428823282743597362012-11-23T21:56:00.001+05:302013-06-08T11:53:47.116+05:30

In Part 1 (link) active sniffing and performing a man-in-the-middle attack were introduced. It allows you to intercept between the communication of two clients and thus able to read all their conversation. In this part tools will be demonstrated with which such an attack can be performed. We will begin with one of the most easy to use and robust tools called Cain and Abel. It is composed

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com1tag:blogger.com,1999:blog-8817173192013879812.post-5615364547957323382012-07-04T16:28:00.001+05:302013-06-08T11:54:06.034+05:30

A long time ago I had written an article (http://anadisays.blogspot.in/2010/06/wireshark-as-sniffer.html) on network sniffers, primarily wireshark, which described what sniffing is and how one can passively sniff other users' data by setting Wireshark in promiscuous mode. Such a technique is known as passive sniffing and is really useful if your local network uses hubs instead of switches.

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com0tag:blogger.com,1999:blog-8817173192013879812.post-13176737851765998482011-09-13T23:30:00.000+05:302013-06-08T11:24:02.798+05:30

Multimedia has become an important part of the Internet nowadays. Consumers have realized that Internet connectivity is as important as a telephone connection and have showed willingness to invest in high bandwidth connection. This has led to a proliferation of rich multimedia websites- youtube is a prime example. Although Youtube and such sites generally offer recorded videos, live streaming is

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com1tag:blogger.com,1999:blog-8817173192013879812.post-78215281765762642252011-09-07T04:38:00.000+05:302013-06-08T11:24:28.612+05:30

In our college someone or the other is always in a search for the ultimate Cyberoam 'bypasser'- something which is undetectable and can run all kinds of services. For all those unaware of Cyberoam, it is a network security product which (at the simplest level) can block websites and applications deemed harmful by the administration. Our administration has blocked most of the sites including

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com7tag:blogger.com,1999:blog-8817173192013879812.post-31093571972312118722011-05-24T00:14:00.000+05:302013-06-08T11:25:00.305+05:30

A couple of previous articles talked about how Microsoft Windows platforms store user passwords and how one can access and crack them to control a PC (links provided at the bottom). Well it is a time consuming process and there is always a chance you may not be able to crack the passwords due to their complexity . It is a bit cumbersome requiring elevated

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com6tag:blogger.com,1999:blog-8817173192013879812.post-41447792440826454082011-05-17T23:29:00.000+05:302013-06-08T11:25:43.710+05:30

A previous article, cracking Windows passwords, talked about how OS passwords are stored, their security and how we can go about cracking and attacking them using bruteforce technique. This is an important aspect of OS hacking and a very notorious topic. Tools such as Ophcrack and JTR(John The Ripper) are available which can use a password file to find out all the passwords. But there is a

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com4tag:blogger.com,1999:blog-8817173192013879812.post-26197672425916897322011-04-20T17:45:00.000+05:302013-06-08T11:27:14.527+05:30

This post is about using Paros Proxy, an application layer proxy server which intercepts all the application layer traffic from a specified port and allows you to modify the content going and coming form different HTTP servers. It is a very useful tool for debuggers designing dynamic websites since it can be used to understand the data being passed. It is a much better tool than Wireshark

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com5tag:blogger.com,1999:blog-8817173192013879812.post-38140212652258831512011-02-28T17:16:00.000+05:302013-06-08T11:32:10.283+05:30

MDD also known as Memory Dump by ManTech is a forensic software tool used to take a snapshot or an image of a computer's memory. Nowadays with increasing loopholes in a system, software memory leaks have become common, programmers forget to deallocate dynamic memory or ensure that sensitive data is not left behind when a software exists. Since movement of data to and fro a regular memory is very

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com0tag:blogger.com,1999:blog-8817173192013879812.post-30404570411175782432011-01-02T01:37:00.000+05:302013-06-08T11:28:55.192+05:30

A couple of previous posts were about    1. Introduction to Vlan    2. Implementation of VLAN in Cisco devices with the help of Cisco Packet Tracer.  A special topology known as Router On a Stick was also mentioned(it is an interesting topic taught in Cisco's CCNA curriculum). In certain situations VLAN prove to be too restrictive since they disallow

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com3tag:blogger.com,1999:blog-8817173192013879812.post-71916378105571321852010-12-29T00:12:00.000+05:302013-06-08T11:30:30.458+05:30

I was quite surprised when I realized that I have not posted a single code on my blog. Unfortunately I am not the programmer one expects to design complex algorithms or solve logical problems in a jiffy. Every semester break, I plan to code small application which involve new languages or something which has not been taught before. The first such attempt involved learning Visual Basic. Visual

Anadi Chaturvedihttp://www.blogger.com/profile/01944351713649066710noreply@blogger.com3