How does the internet work - We know what is networking
Intro Multipath TCP is an extension of TCP that will soon be standardized by IETF. It is a succesful attempt to resolve major TCP shortcomings emerged from the change in the way we use our devices to communicate. There’s particularly the change in the way our new devices like iPhones and laptops are talking across network. All the devices […]
Recently I was in a situation where I needed to advertise some OSPF routes created using the area range command into BGP. When advertising routes into BGP there are a few considerations:
Using the area range command will automatically generate an OSPF intra-area route to Null 0 IF the router the command is issued on is an ABR. This is visible here:
Switch#sh ip route 10.253.0.0 255.255.240.0
Routing entry for 10.253.0.0/20
Known via "ospf 1", distance 110, metric 0, type intra area
Routing Descriptor Blocks:
* directly connected, via Null0
Route metric is 0, traffic share count is 1
This route will not be created on a non-ABR router, so watch Continue reading
In the midst of this series of posts around fast convergence, someone asked if I could explain p and q space a little better. The illustration here might help readers who have more of a visual mind to understand the concepts involved. (feel free to click through to a larger version) Essentially, we can think […]
First Wind Energy is searching for a Network Administrator who will be a key member of the IT team and report to the Director of IT. This position is based in Boston, MA. The Network Administrator is a hands-on technical position focusing on the support and maintenance of the network infrastructure and end user support […]
The post Job Opening – Network Administrator at First Wind Energy, Boston, MA, USA appeared first on Packet Pushers Podcast and was written by Job Posting Service.
MPLS is widely used technology within Service Providers and sometimes also within Enterprise networks. One of the mostly used application of MPLS is MPLS VPN. There are two flavors of MPLS VPN which is Layer 2 and Layer3 VPNs. Basically layer2 VPNs, service provider gives layer2 connectivity to the customer and PW established for each […]
The post INTER-AS VPNs PART -1 appeared first on Packet Pushers Podcast and was written by Orhan Ergun.
Apple releases an iOS update and the networks all across the world witness a spike of almost 100% in the average traffic that they receive. Apple delivers its content using Akamai, which allegedly handles 20% of world’s total web traffic. Akamai is thus in a unique position to provide a view of whats happening on the web, at any given instant in time. Akamai logs clearly show an over all increase in Internet traffic and the hotspots in Europe soon after Apple released its iOS7.
Akamai showing traffic hotspot in Europe
Most service providers saw Akami and Limelight traffic up by an average of 300-700% immediately after iOS7 was released.
Being an Android user myself, i found iOS7′s release with the massive increase in the Internet traffic reported all over the world quite insidious. Honestly, i was a trifle concerned with what iOS7 was internally doing to result this.
It turned out to be quite an anti-climax when i realized that the spurt in network traffic was just because of Apple devices upgrading to the newer iOS. The iOS7 upgrade for the phones is around 900MB, and that for the ipads is around 1.2GB. Given that there are quite Continue reading
In this week’s show, we dive into the networking community ocean, and come up with Brian Tierney and Nick Buraglio for a discussion about perfSONAR. perfSONAR is an open-source package of network testing tools that can run in a mesh across diverse network infrastructure, and help determine why you’re not getting the network throughput on […]
The post Show 163 – Open Source perfSONAR Finds The Flaws Impacting The Flows appeared first on Packet Pushers Podcast and was written by Ethan Banks.
There was a time when the network was flat – everything was interconnected, anyone could access everything and security was not a serious problem. And when security problems began to crop up, options like three-layered hierarchical model, firewalls and Intrusion Detection Systems helped you secure the network. Finally, when you were battling viruses, zero day […]
The post Stop The Rodent – Tackling Rogue Devices in the BYOD Era appeared first on Packet Pushers Podcast and was written by Sponsored Blog Posts.
Last week I participated in the Software-Defined Data Center (SDDC) Symposium and there were a number of interesting conversations generated from the presentations and panels. Topics included thoughts on SDN architectures, how applications are driving changes in the data center and where the money/budgets will flow from with changes in the data center. Craig Matsumoto of SDN Central covered some of the highlights in his piece on “What the SDDC Good for Anyway?”
One topic of discussion that got a strong reaction from panelists was around whether significant organizational changes are needed to build and support an SDDC, and more importantly, how to go about making those changes. Everyone agreed that changes should come, but as Craig pointed out in his article, several speakers advocated a “rip the Band-Aid off” approach to breaking down silos. I can understand why one might think getting changes made all at once makes sense. However, the Embrane team has spent a lot of time thinking this through and speaking to customers about their SDN and SDDC plans, and it’s just not realistic.
While it’s good for enterprises to have a long-term plan for redesigning organizations and operational procedures, a phased approach delivers many Continue reading
Normally I talk about overlays in the context of data center/SDN/cloud but today I’m going out into left field and am going to talk about voice! :-)
I freely admit that I’m a noob when it comes to Cisco voice so I’m not sure if the behavior I’m about to describe is obvious or not. It wasn’t obvious to me and I only figured it out after running into the issue for real and troubleshooting it to resolution.
The issue stems from my misunderstanding about how dual-line ephone-dns function when used in an overlay.
Here’s the scenario: Cisco Communications Manager Express (CME) with a handful of IP phones registered to it. There’s no Communications Manager (UCM); the dial plan lives entirely within CME. PSTN connectivity is via (4) POTS lines terminated on FXO ports on the router running CME.
The desired behavior is to have incoming calls from the PSTN ring on all the IP phones simultaneously. If a second call comes in, it should ring on all the remaining phones, and so on.
Here’s what the original CME config looked like. At least, the parts of the config relevant to this blog Continue reading
Those in technology realize that a day of work can vary greatly and can change without warning. Additionally, many try to build elaborate project plans and organizational goals. However, what is sometimes overlooked is the importance of daily execution of tasks. Those in technology must individually address the need to stay on task each and […]
The post 10 Tips for Daily Time Management appeared first on Packet Pushers Podcast and was written by Paul Stewart.
Normally I talk about overlays in the context of data center/SDN/cloud but today I'm going out into left field and am going to talk about voice! :-)
I freely admit that I'm a noob when it comes to Cisco voice so I'm not sure if the behavior I'm about to describe is obvious or not. It wasn't obvious to me and I only figured it out after running into the issue for real and troubleshooting it to resolution.
The issue stems from my misunderstanding about how dual-line ephone-dns function when used in an overlay.
The mostly nonsense title masks several discussions we have with many of the Networking Field Day 6 delegates around the following topics: Spirent’s new Avalanche NEXT testing platform for network transit and security platforms. What it is, what it does, and what we thought of the live demo we got. Our introduction to the ThousandEyes […]
The post Show 162 – The Bourbonator Rises at #NFD6 appeared first on Packet Pushers Podcast and was written by Ethan Banks.
So –we’ve covered on of the two cases dealing with calculating a new path, and then I left you hanging for a week. What’s the second case? Let’s return to our small network for a moment to figure it out. What happens if D’s cost to reach the destination isn’t lower than E’s cost? E […]
Next Generation Virtualization Demands for Critical Infrastructure and Public Services
Introduction
In recent decades communication technologies have realized significant advancement. These technologies now touch almost every part of our lives, sometimes in ways that we do not even realize. As this evolution has and continues to occur, many systems that have previously been treated as discrete are now networked. Examples of these systems are power grids, metro transit systems, water authorities and many other public services.
While this evolution has brought on a very large benefit to both those managing and using the services, there is the rising spectre of security concerns and the precedent of documented attacks on these systems. This has brought about strong concerns about this convergence and what it portends for the future. This paper will begin by discussing these infrastructure environments that while varied have surprisingly common theories of operation and actually use the same set or class of protocols. Next we will take a look at the security issues and some of the reasons of why they exist. We will provide some insight to some of the attacks that have occurred and what impacts they have had. Then we will discuss the traditional Continue reading
