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How do you monitor your network traffic? Of course using MRTG, you might say. Yes, that’s true, MRTG does an excellent job of monitoring traffic across networks and devices (router/switches). But when you see an abnormal traffic in MRTG, how do you find out what is generating that extra abnormal traffic? This is where ntop comes into play. Basically, MRTG shows you a bigger picture, whereas ntop lets you zoom into individual networks and hosts, and gives you enough information to pinpoint the hosts or devices generating extra/abnormal traffic.

ntop is a tool that shows network traffic usage. It is based on libpcap and when installed in a place where it can capture network traffic (hub or a mirrored port of a switch), it logs and reports information concerning IP and Fibre Channel traffic generated by each host in the network. ntop has a very rich and user-friendly web interface for reporting.

This is what ntop can do for you:

* Sort network traffic according to many protocols
* Show network traffic sorted according to various criteria
* Display traffic statistics
* Store on disk persistent traffic statistics in RRD format
* Identify the indentity (e.g. email address) of computer users
* Passively (i.e. withou sending probe packets) identify the host OS
* Show IP traffic distribution among the various protocols
* Analyse IP traffic and sort it according to the source/destination
* Display IP Traffic Subnet matrix (who’s talking to who?)
* Report IP protocol usage sorted by protocol type
* Act as a NetFlow/sFlow collector for flows generated by routers (e.g. Cisco and Juniper) or switches (e.g. Foundry Networks)
* Produce RMON-like network traffic statistics

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After switching to a mac, I tried many desktop password managers, and had written about Password Managers for OS X, which got a lot of attention. It’s needless to mention the importance of using a password manager since we use passwords to protect almost everything digital, and we’ve so many of them today. Currently we trust most of our private data like, emails, bookmarks, documents, spreadsheets and calendar events to some online providers like Google, Yahoo or Microsoft. So, how about your secrets and passwords stored online, somewhere in the cloud? I know what your immediate response is, passwords? No way I’m going to store my passwords online! But you might want to give a second thought because now the technology is secure enough. Thanks to Host-Proof Hosting. If the owners of the servers wanted to mess around with your information, or even if the server gets hacked, they won’t be able to recover your data. In Host-Proof Hosting the sensitive data is always transmitted to the server in encrypted from using a pass-phrase. The good thing is that, this pass-phrase is never transmitted to or stored in the server. The server can never access the stored data in it’s plain form. All the encryption and decryption takes place in the client side, inside the browser. This is basically a “Zero-Knowledge” web application, where the provider knows nothing about your actual data.

* User enters pass-phrase to begin using the system. Browser retains the pass-phrase as a global variable.
* User requests a list of all data belonging to him.
* For each record, the system stores the associated user ID in plain-text, the record ID in plain form, and the record content only in encrypted form. (The message content is one or more database columns, each encrypted.) Thus, system is able to return a list of record IDs for this user.
* User selects one of the record IDs.
* System checks that this user ID is associated with the record ID, and returns the corresponding message content.
* Browser uses stored pass-phrase to decrypt the contents.

Ok, with that background if you’re ready to store your sensitive information online, here are few choices for you.

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The benefits of designing and testing complex networks in simulated environments are obvious to network professionals and companies. It lets them test the network configurations before implementing it in the real world, and the good thing is that, they can do this without investing any money in expensive hardwares. Virtual networks are also excellent tools for academic and certification purposes like CCNA, CCNP or CCIE, where students can get hands-on experience configuring cisco routers.

Currently Cisco is the leader in Networking market, and Linux, the leader in Server market. So, if you want to test your complex (or not so complex) network configurations before buying any actual linux servers or the very expensive cisco routers, then you can use Dynamips to simulate Cisco Router/Switch and VNUML (Virtual Network User Mode Linux) to simulate your linux servers/routers. Both Dynamips and VNUML are open source and free.

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There are many things you can and should do to keep your system and network secure. As the saying goes — “Security is not a single event or a product, it’s a process”. So, you’ve to keep up with all the changes, installing firewalls, IDS/IPS, network security monitoring, auditing, making security policies, password policies, email policies and so on… Yes, all of them are very important and you’ll be dealing with most them depending on your security requirements. But there’re some basic things every network and system admin should follow. Personally, I’ve found 4 things that are very simple yet effective in securing your systems.

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Snort has always been, and still is my favorite IDS (Intrusion Detection System) although I manage many UTM (Unified Threat Management) Firewalls with built in IPS/IDS (Intrusion Detection/Prevention) now. The commercial UTM Firewalls with IPS/IDS are easy to use and configure but they come with a high price tag and aren’t easy to customize. Even though snort is not that easy to install, configure and manage it still is the most popular IDS/IPS today because of the fact that it is open source, free, easily customizable, easy to create rules, signatures are always kept up-to-date by its community and plenty of excellent documentation, guides and books.

Snort captures enormous amount of data from the network and generates alert based on the rules and signatures. There’re currently 3 excellent and relatively user friendly ways to manage and analyze the snort data:
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Mac OSX Leopard - The latest and greatest Mac OS X, major features unveiled. New Desktop, Finder, Time Machine, Spaces, Quick Look and many more…

Safari for Windows - The sleek and fast apple browser comes to Windows world. I’ve installed it in my windows machine and surfed for a while. The first impression is that, it’s faster than both IE7 and Firefox, but at the same time it’s buggier, in an hour browsing it crashed twice (it’s currently in beta and I’m sure it’ll be fixed soon).

iPhone to Support Third-Party Web 2.0 Applications - So, Apple is allowing the developers to make iPhone apps and host them on their own servers. iPhone is using full Safari-based browser.

WWDC 2007 Keynote (QuickTime Video on Demand) - Watch Apple CEO Steve Jobs unveil and demo Leopard features in his World Wide Developer Conference keynote address from San Francisco’s Moscone West.

Go and download a free DivX Pro for Mac by giving your email address. The license will be sent to your email address. No word on why they’re giving it for free, but who cares. It’s a good chance to get an excellent video player worth 20 bucks for free. I’ve already downloaded and installed mine. Act quickly!

Via: macenstein

Macrumors noted, Sun’s CEO Jonathan Schwartz announcing that Apple would be making ZFS the default filesystem in Mac OS 10.5 Leopard. That’s a great news. So, welcome pooled storage and bye-bye volumes!

ZFS stands for Zettabyte File System and was developed by Sun, it offers many advanced features and can handle much more space than the current filesystems used by Windows, OS X or Linux.

ZFS presents a pooled storage model that completely eliminates the concept of volumes and the associated problems of partitions, provisioning, wasted bandwidth and stranded storage. Thousands of filesystems can draw from a common storage pool, each one consuming only as much space as it actually needs. The combined I/O bandwidth of all devices in the pool is available to all filesystems at all times.

All operations are copy-on-write transactions, so the on-disk state is always valid. There is no need to fsck(1M) a ZFS filesystem, ever. Every block is checksummed to prevent silent data corruption, and the data is self-healing in replicated (mirrored or RAID) configurations. If one copy is damaged, ZFS will detect it and use another copy to repair it.

ZFS introduces a new data replication model called RAID-Z. It is similar to RAID-5 but uses variable stripe width to eliminate the RAID-5 write hole (stripe corruption due to loss of power between data and parity updates). All RAID-Z writes are full-stripe writes. There’s no read-modify-write tax, no write hole, and — the best part — no need for NVRAM in hardware. ZFS loves cheap disks.

I love Firefox for the huge amount of extensions it offers. Lifehack has suggestion for bloggers — 17 Firefox Extensions That Make Blogging Easy.

Do you want to protect your pictures online? The short answer is: you cannot do it, but you can create technical roadblocks and aesthetic roadblocks. Of Zen and Computing has a nice article on How to Protect Your Pictures and Photos on the Internet.

I have tried most of the RSS Readers available including Google Reader but I’ve come back NetNewsWire for the features and ease of use. After seeing the ProBlogger’s poll result on Which Feed Reader is Best? I’m going to seriously give Google Reader another try. Actually, I’m already using it with Google Gears. Check How Google Gears Will Change Your Life.

Every blogger wants the new visitor to come back to their blog again. Wordpress offers many plugins to help you make your blog sticky, and Aaron Brazell at Technosailor suggests some excellent plugins for Intelligent Design and Stickiness

Many smart people have figured out the importance of domain name quite early, and are now multi-millionaires. They came up with many different (smart and weird) business models with the domain name. Check this fascinating story about The man who owns the Internet. Ok that was for business, but how about the domain name for individuals? There’s no doubt that now it’s becoming critical for individuals too. A recent study showed that one in five employer searches the information about the cantidate in internet and 59 percent of those said it influences recruitment decisions. Fortunately you can have your say in what Google says about you. So, individual’s online presence is more important than ever before.

I remember having a hard time finding an appropriate domain name for this site when I started blogging. Today, I decided to check if there were any leftover domain names for me to nab. All the .com, .net and .org domains with my name were already taken. So, I tried my family name, and was lucky to find kunwar.org free. I’ve registered it and forwarded the domains niranjan.kunwar.org and kunwar.org to this site. Maybe in the future I can provide a sub-domain to each and every member of my family . Also found niranjankunwar.com free, and nabbed that too.

If you’re lucky enough to still get a domain with your first name or family name you should just grab it. I register my domains at Netfirms, it’s pretty cheap — $4.95 for first year and $9.95 per year thereafter.

What do you think about online presence and owning your own domain name?