Day two is now in the books, and all I have to say is What a Keynote! I have been coming to Cisco Live for over 10 years now and I will say that this keynote did have something special to it. I think knowing that this was his list keynote as CEO of Cisco, […]
The post Cisco Live 2015 – Monday appeared first on Fryguy's Blog.
Yesterday, I posted about using Vagrant to learn Ansible, in which I showed you one way to combine these two tools to make it easier to learn Ansible. This is a combination I’m currently using as I continue to explore Ansible. Today, I’m going to expand on yesterday’s post by showing you how to make Vagrant automatically build an Ansible inventory for a particular Vagrant environment.
As you may already know, the Vagrantfile that Vagrant uses to instantiate and configure the VMs in a particular Vagrant environment is just Ruby. As such, it can be extended in a lot of different ways to do a lot of different things. In my case, I’ve settled on a design pattern that involves a separate YAML file with all the VM-specific data, which is read by the Vagrantfile when the user runs vagrant up. The data in the YAML file determines how many VMs are instantiated, what box is used for each VM, and the resources that are allocated to each VM. This is a design pattern I’ve used repeatedly in my GitHub “learning-tools” repository, and it seems to work pretty well (for me, at least).
Using this arrangement, since I Continue reading
If you’ve watched any of the recent Wireless Field Day presentations, you know that free wireless is a big hot button issue. The delegates believe that wireless is something akin to a public utility that should be available without reservation. But can it every really be free?
Let’s take a look at other “free” offerings you get in restaurants. If you eat at popular Mexican restaurants, you often get free tortilla chips and salsa, often called a “setup”. A large number of bars will have bowls of salty snacks waiting for patrons to enjoy between beers or other drinks. These appetizers are free so wireless should be free as well, right?
The funny thing about those “free” appetizers is that they aren’t really free. They serve as a means to an end. The salty snacks on the bar are there to make you thirsty and cause you to order more drinks to quench that thirst. The cost of offering those snacks is balanced by the amount of extra alcohol you consume. The “free” chips and salsa at the restaurant serve as much to control food costs as they do to whet your appetite. By offering cheap food Continue reading
Former Quorum CEO signs on to lead SDN startup PLUMGrid.
A fully open-source SDN distribution gets introduced by the ONF.
I’ve been using Junosphere a lot recently, and it’s a great tool – quick and easy creation of topologies without the need to go to a physical lab to try things out. Takes the guesswork out of a lot of things, which is a real bonus. There are obviously a few things you can’t do in a virtual environment that would be possible in a real one (e.g. QoS, MTU greater than 2000 bytes, MS-MIC in an MX), but it caters for 80% of what you need.
I always thought that it put Juniper leagues ahead of Cisco because you can buy credits to use the system right on the front page. Cisco were late to the party with something called VIRL – Virtual Internet Routing Lab. They were late, but rumour had it that a lot of developers moved from Juniper to Cisco to bring VIRL about. However Junosphere always had the edge for the networking student (as we all remain, whether we are JNCIE or not) because of its accessibility – with VIRL you had to be a Cisco customer and gain access through your account manager. I’ll stick with GNS3 thanks!
That appears Continue reading
I’ve been using Junosphere a lot recently, and it’s a great tool – quick and easy creation of topologies without the need to go to a physical lab to try things out. Takes the guesswork out of a lot of things, which is a real bonus. There are obviously a few things you can’t do in a virtual environment that would be possible in a real one (e.g. QoS, MTU greater than 2000 bytes, MS-MIC in an MX), but it caters for 80% of what you need.
I always thought that it put Juniper leagues ahead of Cisco because you can buy credits to use the system right on the front page. Cisco were late to the party with something called VIRL – Virtual Internet Routing Lab. They were late, but rumour had it that a lot of developers moved from Juniper to Cisco to bring VIRL about. However Junosphere always had the edge for the networking student (as we all remain, whether we are JNCIE or not) because of its accessibility – with VIRL you had to be a Cisco customer and gain access through your account manager. I’ll stick with GNS3 thanks!
That appears Continue reading
Note: This is part of a multi-post series I am writing that compares Aruba to HP and how the integration of Aruba Networks into HP might play out. You can read my intro post here.
I am a HUGE fan of vendor ecosystems. A HUGE fan. I have written about them before. The last post I wrote on them can be found here. I really do think they are the key to driving a vendor’s success. One could argue that the large vendors have it easy. They have the resources to build those ecosystems. They can spend money that the smaller vendors cannot and can essentially buy loyalty from customers and partners. Of course, at some point, those large vendors were small ones. They did something different to propel them to the large vendor status. Their competition fell by the wayside and either drifted off into obsolescence, or just outright died.
Sorry. There is no TL/DR for this post. Buckle up. It’s a long one.
So let’s get a lay of the land when it comes to ecosystems between HP and Aruba. Let me clear about one thing. This is specific to wireless. This has nothing to do with the Continue reading
The first batch of the latest materials for my Designing Scalable Web Applications course have been published on my free content web site.
One of the truly fascinating things about networking is how much of it ‘just works’. There are so many low level pieces of a network stack that you don’t really have to know (although you should) to be an expert at something like OSPF, BGP, or any other higher level networking protocol. One of the ones that often gets overlooked is MTU (Maximum Transmission Unit), MSS (Maximum Segment Size) and all of the funs tuff that comes along with it. So let’s start with the basics…
Here’s your average looking IP packet encapsulated in an Ethernet Header. For the sake of conversation, I’ll assume going forward that we are referring to TCP only but I did put the UDP header length in there just for reference. So a standard IP packet is 1500 bytes long. There’s 20 bytes for the IP header, 20 bytes for the TCP header, leaving 1460 bytes for the data payload. This does not include the 18 bytes of Ethernet headersFCS that surround the IP packet.
When we look at this frame layout, we can further categorize components of the frame by MTU and MSS…
The MTU is defined Continue reading