CCDE Training
I am very pleased to announce that my student Hamed Zolghadri passed the CCDE Practical exam in February, and now he has joined the CCDE club
The post CCDE Training appeared first on Network Design and Architecture.
The F-Script – Now on GitHub
A while back I posted about my “f-script”, a tool that reads device configurations and extracts IP/subnet information so that it can quickly and easily queried to find where an IP might exist on the network, and what else is on the same subnet.
I was also lucky enough to take part in an early episode of Ivan Pepelnjak’s “Software Gone Wild” podcast where I talked about network automation and in particular, the f-script. In that podcast I promised that I would put the f-script up on GitHub once I had the time to clean it up a little and remove things that tied it to a particular environment.
At the end of 2014 I finally uploaded the scripts, and you are now in the lucky position of being able to laugh at how badly it’s written (and really, it is) or, better still, to help me improve it by submitting your own edits. Bear in mind that this started off as a hack (“I’ll do it like this just to prove that it can work”) and as with so many temporary solutions, ended up never being rewritten “properly”. Still, it works and has been pretty Continue reading
Using Vagrant with CoreOS, etcd, fleet, and Docker
As a follow-up to my recent #vBrownBag session on “Docker and Friends,” I wanted to provide a quick and relatively easy way for VMware administrators to experiment with some of the technologies I demonstrated. Since not everyone has their own OpenStack cloud running in their basement, Vagrant seemed like a reasonable solution. So, in this post, I’ll show you how to use Vagrant to experiment with some of the technologies I demonstrated in the #vBrownBag session.
If you’d like to follow along on your own, I’ve uploaded the necessary files to the GitHub repo I created for the #vBrownBag session. Just have a look in the coreos-vagrant folder in that repository.
What You’ll Need
- Vagrant (I tested with Vagrant 1.7.2)
- VMware Fusion (I used Fusion 6.0.5 on OS X 10.9.5)
- the VMware plugin for Vagrant
- the CoreOS Vagrant box for the
vmware_fusionprovider (more on that in a moment) - the necessary supporting files (more on that in a moment as well)
I’m not going to cover installing Fusion, Vagrant, or the VMware provider for Vagrant, as those steps are reasonably well-documented by the respective vendors. I will, though, talk about getting the CoreOS box Continue reading
Updating the DNS Registration Model to Keep Pace with Today’s Internet.
CloudFlare is, arguably, the largest third-party DNS Authoritative operator in the world. We manage well over 1 million domains and have registrations in almost every TLD open for registrations. Our role as a DNS operator is to maintain customer information and publish their records in the global DNS.
In this blog, we’ll introduce a significant problem that DNS operators like CloudFlare face when trying to provide the best possible experience to our customers. If you are a CloudFlare customer, you’ll remember during the sign up process you were asked to login to your registrar account in order to change your nameservers (NS). The absence of an automated process for changing NS records not only makes our signup process one step longer than we’d like, it also prevents CloudFlare, and other 3rd party DNS operators, from doing a slew of other things that would benefit customers and the Internet as a whole.
Note: In this blog we’ll use the term DNS Operator mainly in the context of operators that provide Authoritative DNS service. This is sometimes called Managed DNS service.
Manual Updates
For those who are not yet CloudFlare customers, let’s run through the sign up process:
When CloudFlare customers enable Continue reading
Networking Field Day 9: Fresh Perspectives on Open Networking
The community-selected delegates of Networking Field Day 9 #NFD9 are coming to Cumulus Networks on February 11, 12:30pm-2:30pm PST, to learn more about open networking – and it’s going to be live streamed for everyone, so mark your calendar.
We’ve assembled a team of industry experts from Cumulus Networks to discuss with 13 NFD9 delegates data center evolution and what makes us different.
The topics to be presented are:
- Overview and what makes Cumulus Linux compelling — JR Rivers, co-founder and CEO
- Data center architectures and how we make it easier to build networks — Dinesh Dutt, Chief Scientist
- Data center network operations and how we make it easier to manage networks — Matt Peterson, Office of the CTO
- Real world examples, from a network admin to a cloud admin — David Sinn, Customer Solutions Engineer
Networking Field Day is not just a one-way presentation; it brings us together with independent thought leaders to share information and opinions in a presentation and discussion format. If you’re a networking technologist, this is a great opportunity for you to join the live stream and participate in the discussions on Twitter #NFD9 and @CumulusNetworks. If you’ve heard about open Continue reading
Network Dictionary: Mean Time to Innocence
Define "Mean Time to Innocence"
The post Network Dictionary: Mean Time to Innocence appeared first on EtherealMind.
MITM’ing TLS/SSL for debugging purposes
MITM’ing TLS/SSL for debugging purposes
From time to time you may want to debug TLS, Now this is not as easy as you might think, Because of the nature of TLS, you don’t really want to have anyone (even if they technically may have the key on the se
Network Break 27
Coffee, doughnuts and networking. A perfect combination.
Author information
The post Network Break 27 appeared first on Packet Pushers Podcast and was written by Greg Ferro.
Response: IEEE 802.3by – Inventing Their Own Problems to Solve Them
The IEEE actually moved faster than a dead turtle and has a PAR for 25GbE. Except now they are inventing problems that don't need solving and demonstrating how much stupid they can achieve.
The post Response: IEEE 802.3by – Inventing Their Own Problems to Solve Them appeared first on EtherealMind.
We Need to Move from Assembling Car Parts to Driving Cars
During a great conversation I had with Terry Slattery during Interop New York, he said “well, I don’t think anyone should be configuring VLANs and asking ÔÇśHow to configure a VLAN on a switch’ – we should be focused on providing end-to-end connectivity”, and there’s absolutely nothing in that statement that one could disagree with.
Read more ...From VIRL to IOU and Back
When VIRL first came out everyone jumped on the bandwagon, including myself. Some of us have had it before it was officially released to the public...[[ Summary content only, you can read everything now, just visit the site for full story ]]
EIGRP SIA (Stuck-In-Active) through animations.
EIGRP SIA (Stuck-In-Active) process through animations: “Active” = Actively looking for a route to a network (Successor) Without SIA Browse in separate page With SIA Browse in separate pageFiled under: Animation, Routing protocols Tagged: EIGRP, feasible successor, sia, sia-query, sia-reply, stuck-in-active, successor
EIGRP SIA (Stuck-In-Active) through animations.
EIGRP SIA (Stuck-In-Active) process through animations: “Active” = Actively looking for a route to a network (Successor) Without SIA Browse in separate page With SIA Browse in separate pageFiled under: Animation, Routing protocols Tagged: EIGRP, feasible successor, sia, sia-query, sia-reply, stuck-in-active, successor
Networking Field Day 9 First look: Generation-SDN -Part 1
If there is one topic prevalent at Networking Field Day #9 it is SDN, well okay maybe this is one of the most prevalent topics in the networking industry right now. Among many the presenters at Networking Field Day #9 quite a few of them bring some flavor of SDN or SDN-WAN’s to the table. A few […]
New CCIE RSv5 Workbook Troubleshooting & Full Scale Labs Posted
Troubleshooting Lab 3 and Full Scale Lab 3 have now been added to the CCIE RSv5 Workbook!
The new Troubleshooting Lab 3 uses the Full Scale Lab 1 logical topology, but breaks all of the protocols you’ve previously built. I suggest you take your time with each ticket so that you can fully digest why each fault occurs. Practice your time and knowledge skills by taking the Troubleshooting Lab 3 challenge!
Full Scale Lab 3 is built on a brand new logical topology, and has a strong focus in MPLS and BGP technologies. The solution guide features detailed breakdowns of each topic domain to give you a better understanding of the solutions used to solve each task. Keep in mind that there are multiple ways to solve most problems.
For discussion on these new labs visit our online community, IEOC.
Enjoy!
Path MTU discovery in practice
Last week, a very small number of our users who are using IP tunnels (primarily tunneling IPv6 over IPv4) were unable to access our services because a networking change broke "path MTU discovery" on our servers. In this article, I'll explain what path MTU discovery is, how we broke it, how we fixed it and the open source code we used.
First there was the fragmentation
When a host on the Internet wants to send some data, it must know how to divide the data into packets. And in particular it needs to know the maximum size of packet. The maximum size of a packet a host can send is called Maximum Transmission Unit: MTU.
The longer the MTU, the better for performance, but the worse for reliability, because a lost packet means more data to be retransmitted and because many routers on the Internet can't deliver very long packets.
The fathers of the Internet assumed that this problem would be solved at the IP layer with IP fragmentation. Unfortunately IP fragmentation has serious disadvantages and it's avoided in practice.
Do-not-fragment bit
To work around fragmentation problems the IP layer contains a "Don't Fragment" bit on every IP packet. Continue reading
A Baker’s Dozen, 2014 Edition
As is our annual tradition, this blog provides a year-end review of how the Internet providers at the top of our IP Transit Intelligence global rankings (formerly, Renesys’ Market Intelligence) fared over the previous year. The structure and performance of the Internet remains a huge blind spot for most enterprises, even those critically dependent on it for business operations. Whether it’s the next 3 billion people coming online, poor performance due to suboptimal routing, or security breaches of a trust-based Internet infrastructure, Dyn provides critical insight into the structure and performance of the Internet, both real-time and historical, via its Internet Intelligence products. More importantly, our services help our customers make the changes necessary to optimize Internet availability, reliability, and reach. This blog reviews a single very small slice of our data related to the sizes of the top global players as it pertains to the markets and customers they serve.
Back in 2008, we chose to look at the 13 providers that spent at least some time in the Top Ten that year, hence the name “Baker’s Dozen“. We repeated that exercise in 2009, 2010, 2011, Continue reading
From VIRL to IOU and Back
When VIRL first came out everyone jumped on the bandwagon, including myself. Some of us have had it before it was officially released to the public. Cisco’s VIRL is really a good piece of software,...[[ Summary content only, you can read everything now, just visit the site for full story ]]
From VIRL to IOU and Back
When VIRL first came out everyone jumped on the bandwagon, including myself. Some of us have had it before it was officially released to the public. Cisco’s VIRL is really a good piece of software,...[[ Summary content only, you can read everything now, just visit the site for full story ]]