Paessler Blog
Archive for Category "Networking Basics"
2011-Dec-20
How to Setup a Failure Tolerant Online Business in Six Steps—Step 6: Know Your Costs
When monitoring and evaluating which failure tolerant setup is best for your needs, make sure you are aware of the costs. This is the final step and can also be very helpful when evaluating classic hosting vs. cloud hosting for your website or even your office IT.
2011-Dec-13
How to Setup a Failure Tolerant Online Business in Six Steps—Step 5: Monitor Your Network
Once you've set up backup and recovery plans, make sure you know about the status of all of your systems: Your IT infrastructure including all crucial hardware components, your network connections, as well as your servers.
2011-Dec- 6
How to Setup a Failure Tolerant Online Business in Six Steps—Step 4: Have Backup and Disaster Recovery Plans
Your IT infrastructure is secured? Good. But what about your data backup? And are there any plans in case of a business emergency?
2011-Dec- 2
Beautiful Testing
If monitoring software is your business, there is one thing you cannot have enough of: Test systems running all over your network, under many different platforms, and on different hardware configurations.
2011-Nov-29
How to Setup a Failure Tolerant Online Business in Six Steps—Step 3: Set Up Redundancy and Auto-Healing for Your IT Infrastructure
If you made sure that your website is permanently online, you should also provide redundant systems for your office and back office IT.
2011-Nov-22
How to Setup a Failure Tolerant Online Business in Six Steps—Step 2: Set Up Redundancy and Auto-Healing for Your Website
Providing redundancies is essential. If technically possible we always try to set up "auto-healing" mechanisms which kick in immediately whenever a failure happens.
2011-Nov-15
How to Setup a Failure Tolerant Online Business in Six Steps—Step 1: Choose a Reliable Hosting Provider
Thing number one is to have a website that's online and working (and to make it really fast). Many younger companies seem to head straight for the cloud, mainly to market leader Amazon EC2 or Rackspace Cloud. We don't.
2011-Sep- 5
We were Moving: at 67 Gigabit per Second
"Never underestimate the bandwidth of a station wagon
full of tapes hurtling down the highway."
Tanenbaum, Andrew S. (1996).
Computer Networks.
New Jersey: Prentice-Hall.
2010-Dec-22
PRTG Takes Part in Big RIPE Atlas Project
Creating a “weather map” showing the condition of the Internet all over the world is the declared goal of the Atlas project initiated by regional internet registry organization Réseaux IP Européens Network Coordination Centre (RIPE NCC). Located in the Netherlands, they aim to ship small hardware “probes” to all over the world. Volunteers on five continents are asked to plug in these small Ethernet devices into their personal or company’s network, building measuring points for “the last mile” of Internet access points in a large number of countries.
One of the subjects that should be investigated is the suitability of IPv6 in everyday use. As we all have to prepare for this, this project can be very important to all of us. According to Daniel Karrenberg from RIPE, these probes do not sniff any of the participants’ network traffic, but only perform measurements using Ping, DNS resolution via both IPv4 and IPv6, and trace route. RIPE already has longstanding experience in monitoring the traffic at Internet Service Providers, but the Atlas project will extend knowledge about the on and on growing Internet just into the homes. First—statistically unproven—monitoring results are already available.
2010-May-17
"Real World" Performance Comparison of CDN (Content Delivery Network) Providers
Since February visitors of our website http://www.cloudclimate.com have the possibility to measure "website asset delivery speed" of 24 CDN and cloud providers using their own internet connection (see the blog post). The results for each user are stored in our database and we now have gathered the performance results of 340,000 requests. There is something special about our test: We have "real surfer" measurements for the 24 providers because we have actually used the "real world" Internet connections of our website visitors to run the test requests. Most CDN comparison tests that we have seen published on the Internet were created by using just a few measurement points, and often - to make things even more unrealistic - the measurements were taken out of professional data centers (which, in most cases, have high speed connectivity anyway). 24% of the tests were run from inside the USA, 9% each from Germany and the UK, the rest came from countries all over the world. So now it is time to dive into the data and draw some conclusions.2010-Mar-18
First results: Which CDN Provider serves you fastest?
10 days ago I have announced our globally distributed CDN speed test on this blog. At CloudClimate.com we have developed a CDN Performance Test suite that Internet users can run over their personal Internet connection. The test performs ten downloads of a 64 Kbyte image from 12 selected CDN hosting companies plus 12 cloud servers running in public clouds around the globe. Thanks to all users who have visited the webpage in the mean time. We now have logged the results from 66.000 test requests in our database and I can go ahead and publish our first results.
2010-Mar- 8
Big CDN Provider Test: Who Serves You Fastest?
Nowadays, state of the art websites use CDNs (Content Delivery Networks) to deliver static websites assets like images, CSS, and JavaScript files. In order to deliver these objects as fast as possible to the website visitor, the CDN providers run a network of so called "edge servers" in multiple locations. As soon as your browser requests a website object, its connection is directed to the nearest server (in a network topological view) which finally delivers the data. This sounds great in theory, but in real life it can be a complex task. One aspect is running an edge server network around the world (largest provider Akamai reports more than 40,000 servers around the globe). And there is "the last mile" issue: Website visitors usually do not sit in data centers with fiber optic connections, but use cable, DSL, T1, etc. instead. With a broadly conceived test, we want to find out:2009-May-26
Introducing Paessler Multi Server Simulator
For testing purposes Multi Server Simulator simulates a virtual network of HTTP, FTP, SMTP, or DNS servers plus any number of SNMP-based switches - all on a standard Windows PC. It is an indispensable tool for the evaluation and testing of network management and network testing tools.2009-May-20
Monitoring the Birth of a Search Engine - Wolfram|Alpha Goes Online
Over the last weekend the engineers of Wolfram Research gradually launched their new search engine Wolfram|Alpha (or should I better say "knowledge engine"). We monitored their website during this launch with PRTG Network Monitor and here are the results!2009-Apr- 3
The Browser War Revisited (Part 3): Which Browsers Do People Use Around the World?
In the last weeks I have looked at the currently available web browsers from a "performance-for-PRTG" perspective and found that Chrome and Firefox are our recommendations for PRTG. Today I ran across the StatCounter Global Stats website where web analytics service Statcounter publishes its stats about browser usage worldwide.2008-Aug-20
How can I monitor my available bandwidth 24/7?
We receive questions like this every few days. User of our monitoring products want to know if their ISP or hosting service is actually providing them with the available bandwidth that they are paying for. But measuring the actually available bandwidth is almost impossible. Let me explain this:2007-Oct-19
Handy SNMP resources on the Cisco website: Cisco MIB Listings, MIB Locator, and OID Translator
Recently we came across the following three pretty notable pages provided by Cisco, allowing users to find Cisco MIBs and to discern OID segment almost at a glance.2006-Oct- 9
IE7 Is Coming This Month... Paessler Products Are Ready!
IE7 will available later this month and in the coming weeks it will be installed automatically (!) on all Windows systems on the planet via the automatic update service. Are you ready? At least your installations of Paessler software products are!2006-Oct- 3
The Multi-Browser Appliance
An administrator has to make sure that all users inside his LAN as well as visitors accessing his public web servers from the outside are enjoying a good user experience. Webpages must load fast, should look nice and the web applications must work. With so many different browsers out there it can become a daunting task to keep one's websites working on all of them. Today we are looking at an impressive VMWare appliance that helps a lot in this task!2006-Sep-29
How LAN Switches Work
The "How Stuff Works" website has a neat introductory article that explains how switches work. It is obviously based on a technical document from the Cisco website which was enhanced with various networking fundamentals. The article actually goes into some serious detail, even Spanning Tree, VLAN Trunking and more are explained. Makes a good reading for lunch!2006-Aug-24
Easy to read Drawings of IP, TCP and UDP Packet Headers
This is some quite technical information, but it may help you to understand the foundations of everyday networking. Matt Baxter has some drawings that will show you how the structure of the headers for IP, TCP, UDP and ICMP looks byte-by-byte. It is just the normal information from the RFCs presented in an easy to read format.
2006-Aug-16
The art of network troubleshooting
Grag Schaffer has published an article on computerworld.com about his approach to network latency hunting and troubleshooting. Makes a nice reading over lunch.While the technology has changed, the basic methods for troubleshooting networks really haven't. Sure, there are fancier sniffers, analyzers and monitors, but the real basics that demand an understanding of networking to the core level remain the same. Let me present a case history from the days of Thinnet to illustrate.