Author: Calin

Calin is a network engineer, with more than 20 years of experience in designing, installing, troubleshooting, and maintaining large enterprise WAN and LAN networks.

IETF to explore new routing technique

ietf-logoThe IETF is forming a new working group to address scalability issues in the Internet’s routing system caused by companies splitting their network traffic over multiple carriers, a practice called multihoming.

The new working group will build upon a base proposal from a team of Cisco engineers to create a new tunneling mechanism that will be used by the Internet’s edge and core routers.

The new mechanism — dubbed LISP for Locator/Identifier Separation Protocol — is designed to reduce the number of entries in the routing tables stored in the core routers operated by ISPs.

LISP logically separates a block of IP addresses that a company advertises out to the global Internet via its edge routers into two functions: one for identifying the systems using the IP addresses, and the other for locating where these systems connect to the Internet. This separation allows LISP to aggregate the location information, so less of it needs to be stored in the core routers.

Read the full article on NetworkWorld.com…

Cisco security updates squash router bugs

CiscoCisco has released eight security updates for the Internetwork Operating System (IOS) software used to power its routers.

The patches were released Wednesday, the day Cisco had previously scheduled for its twice-yearly IOS updates. None of the bugs had been publicly disclosed ahead of Wednesday’s updates, but some of them were reported to Cisco by outside sources.

Most of the bugs could be exploited by attackers to crash or somehow disrupt service to a router, typically if a specific, vulnerable service is enabled, Cisco said.

The eight updates fix 11 security vulnerabilities, according to Jean Reese, senior manager with Cisco’s Product Security Incident Response Team.

Read the full article on NetworkWorld.com…

Vote Earth! Switch Off Your Lights For Earth Hour

This post has nothing with tech section…or maybe everything!

earthhour_335x500Cuddling up with your loved ones and admiring the stars in the night sky or organising a treasure hunt in the dark? At 8:30pm on Saturday 28 March, people from all corners of the world will turn off their lights for one hour – Earth Hour – and cast their vote for action on climate change. Anybody can participate and join together with millions of people across the globe celebrating Earth Hour.

Earth Hour is about taking simple steps everyday that collectively reduce carbon emissions – from businesses turning off their lights when their offices are empty to households turning off appliances rather than leaving them on standby.

Here are 10 different ways to spend Earth Hour and reduce your carbon footprint:

1. Attend a local Earth Hour event or organise your own by throwing an Earth Hour street party with your neighbours
2. Gather family & friends for a night picnic in your local park and look at the stars
3. Enjoy a family dinner by candlelight
4. Organise a treasure hunt in the dark
5. Take the dog for a night walk
6. Have a candle-lit bath
7. Sit in the dark and share stories
8. Organise a family night playing board games
9. Share a romantic night in with your loved one
10. Upload your ‘on the night’ photos and videos to flickr and YouTube respectively, and then add them to the Earth Hour flickr group and the global YouTube Group.

Earth Hour Executive Director, Andy Ridley, is encouraging people to participate in whatever way they choose and to think beyond the hour.

“There are no hard and fast rules surrounding participation in Earth Hour. We only ask that you flick that switch and have fun doing whatever you choose to do during that time.

Make Earth Hour work for you. Families with young children should feel free to turn their lights off earlier than 8:30pm and for those having too much fun in the dark during the hour, don’t feel you have to limit yourself to one hour and switch back on at 9:30pm.”

To find out more about Earth Hour, visit the official website www.earthhour.org, sign up and join millions of people in more than 1,400 cities and towns in 80 countries throughout the world by turning off your lights for one hour at 8:30pm on Saturday 28 March.

Note: Original post from EarthHour.org



How to integrate GNS3 with Virtual PC

In this article I want to show you how to extend your posibilities to test a network in GNS3. Sure, it’s simple sometime to use a Loobpack interface on one of your edge routers to simulate an external network, but sometime is useful to have something connected to the router port. Take as an example QoS marking and classification. If you want to mark something inbound, then you need a connection to the router port where you want to mark the packets.

Additional to my example here, which include Virtual PC Simulator, you can find useful tutorial about GNS3 and VMware integration on  gns3-labs.com or how to emulate a voice lab with the same tools on blindhog.net.

Even most of you are familiar with GNS3 and maybe Virtual PC Simulator, let me begin with some short description about this 2 software.


GNS3 is a Graphical Network Simulator that allows emulation of complex networks. It allows you to run a Cisco IOS in a virtual environment on your computer (running Linux, MacOS X or Linux). GNS3 is a graphical front end to a product called Dynagen. Dynamips is the core program that allows IOS emulation.

The Virtual PC Simulator (VPCS) allow you to simulate up to 9 PCs. You can ping/traceroute them, or ping/traceroute the other hosts/routers from the virtual PCs when you study the Cisco routers in the Dynamips. VPCS is not the traditional PC, it is just a program running on the Linux or Windows, and only few network commands can be used in it. But VPCS can give you a big hand when you study the Cisco devices in the Dynamips. VPCS can replace the routers or VMware boxes which are used as PCs in the Dynamips network.

Before we start, I assume that you already have these tools installed. If not, please download and install GNS3 and VPCS.

On the following example I will show you how to configure a network topology including 2 Virtual PCs and one router and how to interconnect them in GNS3. This presentation is simulate a basic network, but after you learn how to do it, you can configure more complex one. You can have a look to the topology to understand better what I’m talking about.

Please see the video presentation below:

gns3-virtualpc

Other bloggers article that you might be interested in:

What it will take for mobile VoIP to get enterprise-ready

voipBy all rights, mobile VoIP sounds like an enticing proposition for a lot of companies.

After all, what enterprise wouldn’t jump at the opportunity to save money on their mobile phone bills by sending their wireless calls over an IP network rather than a cellular network? But despite this attractive premise, current mobile VoIP technology has yet to evolve to the point where users can simply switch on their phones anywhere and expect to connect to a secure IP network.

The obvious reason for this is because mobile VoIP devices today are reliant upon Wi-Fi technology, which can offer quality voice service but which also has limited range and is prone to coverage gaps that make it problematic as a voice technology. These factors have so far limited mobile VoIP offerings to office environments or home environments where workers can securely connect to local hotspots to get a dedicated voice channel. But Stan Schatt, an analyst at ABI Research, says that these in-office, in-house technologies have not yet matured enough to the point where they can properly support more complicated applications such as conference calling.

Read the full article on NetworkWorld.com…