I had the good fortune last week to read a great post from Maish Saidel-Keesing (@MaishSK) that discussed security models in relation to candy. It reminded me that I’ve been wanting to discuss security models in relation to desserts. And since Maish got me hungry for a Snicker’s bar, I decided to lay out my ideas.
When we look at traditional security models of the past, everything looks similar to creme brûlée. The perimeter is very crunchy, but it protects a soft interior. This is the predominant model of the world where the “bad guys” all live outside of your network. It works when you know where your threats are located. This model is still in use today where companies explicitly trust their user base.
The creme brûlée model doesn’t work when you have large numbers of guest users or BYOD-enabled users. If one of them brings in something that escapes into the network, there’s nothing to stop it from wreaking havoc everywhere. In the past, this has caused massive virus outbreaks and penetrations from things like malicious USB sticks in the parking lot being activated on “trusted” computers internally.
A Slice Of Pie
A more modern security Continue reading
How Service Providers are Outpacing Enterprises in SDN Deployments
Service providers are well ahead of enterprises in SDN deployments. The numbers confirm this according to Jim Duffy in his Network World article “Enterprise SDN use lags service providers.” ACG Research estimates that sales of SDN products for live service provider deployments will reach $15.6 billion by 2018, while those that may become live will reach $29.5 billion. Use of production SDNs by enterprises and cloud/service provider data centers will be a fraction of that according to Infonetics Research: $3.1 billion by 2017.
Why are service providers so far ahead of enterprises? To paraphrase the oft-used political aphorism: It’s the business model, stupid. Duffy said it best in his article: “To service providers, the network is the business. To enterprises, the network enables or supports its core business.”
To a network service provider, technology is the revenue generator in a competitive market. Better solutions and better technology lead to lower costs (and more profits), and/or competitive differentiation.
Of course, competitive differentiators tend to become commodities over time, and we’ve seen that happen repeatedly Continue reading
While prepping for CCIE Data Center and playing around with a lab environment, I ran into a problem I’d like to share.
I was setting up a basic OTV setup with three VDCs running OTV, connecting to a core VDC running the multicast core (which is a lot easier than it sounds). I’m running it in a lab environment we have at Firefly, but I’m not going by our normal lab guide, instead making it up as I go along in order to save some time, and make sure I can stand up OTV without a lab guide.
Each VDC will set up an adjacency with the other two, with the core VDC providing unicast and multicast connectivity. That part was pretty easy to setup (even the multicast part, which had previously freaked me the shit out). Each VDC would be its own site, so no redundant AEDs.
On each OTV VDC, I setup the following as per my pre-OTV checklist:
BGP in the data center? And MPLS? Are you insane? Well, maybe, yes. But then again, I’ve been known to do a lot of crazy things in my time. Isn’t MPLS a core and edge service provider technology, while VXLAN is an enterprise data center technology? But let’s begin with this idea that technologies are […]
I received an email last week from a reader seeking advice on a fairly common predicament:
Our CIO has recently told us that he wants to get rid of MPLS because it is too costly and is leaning towards big internet lines running IPSEC VPNs to connect the whole of Africa.
As you can imagine, this has caused a huge debate between the networks team and management, we run high priority services such as Lync enterprise, SAP, video conferencing etc. and networks feel we need MPLS for guaranteed quality for these services but management feels the Internet is today stable enough to run just as good as MPLS.
What is your take on the MPLS vs Internet debate from a network engineer's point of view? And more so, would running those services over Internet work?
This is something I struggled with pretty frequently in a prior job working for a managed services provider. MPLS WANs are great because they provide flexible, private connectivity with guaranteed throughput. Most MPLS providers also allow you to choose from a menu of QoS schemes and classify your traffic so that real-time voice and video services are treated higher preference during periods of congestion.
Unfortunately, Continue reading
Another World Cup is in the books, and it’s fair to say that most people will remember 2014 for the inglorious and improbable performance of the host nation, losing 7-1 and 3-0 in its semifinal and consolation matches. Brazil’s sad exit capped off a year of soul-searching about the nation’s massive investment in hosting the World Cup (and the Olympics yet to come).
But Brazil shouldn’t lose sight of one important silver lining to their World Cup cloud: the startlingly vibrant development of the Brazilian Internet, and the critical role Brazil now plays in the Internet connectivity and ICT development of South America.
| Preparations for the World Cup and the Olympics may have helped light a fire under Brazil’s Internet infrastructure providers. Here’s a plot of the growth of the set of autonomous systems (that is, enterprises and service providers who originate IPv4 address space under their own registered Autonomous System Number) in Brazil over time. For comparison, we’ve also included the same statistic for South Africa. By this measure, the two World Cup host countries couldn’t be more different! |
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Brazil and South Africa invite comparison because of their many parallels: Continue reading
This week, Packet Pushers’ hosts Ethan Banks and Greg Ferro queue up a discussion about a new technology, exploring EVPN with Russ White & Jeff Tantsura from Ericsson. What’s EVPN? Well, it’s short for Ethernet VPN, and it’s a way of using BGP as a routing system for MAC addresses. If that sounds like SPB […]
The post Show 196 – EVPN Introduction & Use-Cases with Russ White + Jeff Tantsura appeared first on Packet Pushers Podcast and was written by Ethan Banks.
In the process of restudying EIGRP as a protocol, and more specifically as to how it converges, you can’t avoid running into the saying “Remember to bound your queries!”.
From a conceptual point of view its fairly easy to understand that the further out you ask for a prefix the longer the convergence process will take. But what really takes place when you have different tools in place to bound the query from taking place?
There are 3 different types of “Query Bounding” techniques that can be utilized:
1) Filters (fx. distribute lists).
2) Summarization
3) Stub routers.
How do they actually work to limit the query scope?
Well, the basic premise for EIGRP queries is the fact that you are asking your fellow EIGRP neighbour for an exact prefix, fx. 172.16.1.0/25. If for any reason you EIGRP neighbour does not have this in his topology table, it will simply respond right away that it doesn’t have a path to this prefix. Query stopped right there.
By using filters such as distribute lists you are removing the prefix from ever getting advertised to the neighbour and as such he will never receive it in his topology Continue reading
I wanted to take a few minutes to share a scenario that some seem to struggle with. This scenario is a routing issue that sometimes occurs when an interior routing protocol allows routes to leak back through a tunnel. To demonstrate this, I’ve built a lab with three routers. R1 and R3 are participating in EIGRP and have a GRE tunnel configured directly between them.
hostname R1 ! interface FastEthernet0/0 ip address 192.168.12.1 255.255.255.0 ! interface Tunnel0 ip address 192.168.13.1 255.255.255.0 tunnel source 192.168.12.1 tunnel destination 192.168.23.3 ! router eigrp 1 network 192.168.0.0 0.0.255.255 ! ip route 0.0.0.0 0.0.0.0 192.168.12.2
hostname R2 ! interface FastEthernet0/1 ip address 192.168.12.2 255.255.255.0 ! interface FastEthernet0/1 ip address 192.168.23.2 255.255.255.0 !
hostname R3 ! interface FastEthernet0/1 ip address 192.168.23.3 255.255.255.0 ! interface Tunnel0 ip address 192.168.13.3 255.255.255.0 tunnel source 192.168.23.3 tunnel destination 192.168.12. Continue reading
VyOS is a community fork of Vyatta, a Linux-based network operating system that provides software-based network routing, firewall, and VPN functionality. The VyOS project was started in late 2013 as a community fork of the GPL portions of Vyatta Core 6.6R1 with the goal of maintaining a free and open source network operating system in response to the decision to discontinue the community edition of Vyatta.
VyOS runs on both physical and virtual platforms. It supports paravirtual drivers and integration packages for virtual platforms. It is completely free and open source.
The aim of the tutorial is to show VyOS installation on Qemu virtual machine and get it working on GNS3.
VyOS Qemu and VirtualBox virtual disks can be downloaded here.
I created a Bash script deploy_vyos for automatic deployment of VyOS to Qemu image. The script downloads stable VyOS ISO image from the Internet, creates Qemu disk and starts Qemu virtual machine with attached ISO image. Then is starts Expect script install_vyos that automatically configure all required configuration options without user intervention.
Just copy both scripts to the same directory, assign run privileges to both scripts with the command below and run the deploy_vyos script.
$ chmod +x Continue reading
“Hey Fish, how good are you at BFD? None of my BFD neighbors will come up.” Two simple sentences and I am “hooked.” I love troubleshooting! Troubleshooting is just a blast for me! It’s like being a Network Detective trying to figure out “whodunit” As I sit down in front of the CLI and the […]
The post Confessions of a Troubleshooting Junkie appeared first on Packet Pushers Podcast and was written by Denise "Fish" Fishburne.
[This post was co-authored by Bruce Davie and Ken Duda]
Almost a year ago, we wrote a first post about our efforts to build virtual networks that span both virtual and physical resources. As we’ve moved beyond the first proofs of concept to customer trials for our combined solution, this post serves to provide an update on where we see the interaction between virtual and physical worlds heading.
Our overall approach to connecting physical and virtual resources can be viewed in two main categories:
The latter topic is something we’ve addressed in some other recent posts (here, here and here) — in this blog we’ll focus more on how we deal with physical devices at the edge of the overlay.
We first started working to design a control plane to terminate network virtualization overlays on physical devices in 2012. We started by looking at the information model, defining what information needed to be exchanged between a physical device and a network virtualization controller such as NSX. To bound the problem space, Continue reading
This was an internal email that I sent to the CloudFlare team about how we are not afraid to throw away old code. We thought it was worth sharing with a wider audience.
Date: Thu, 10 Jul 2014 10:24:21 +0100 Subject: Courage to change things From: John Graham-Cumming To: Everyone Folks, At the Q3 planning meeting I started by making some remarks about how much code we are changing at CloudFlare. I understand that there were audio problems and people may not have heard these clearly, so I'm just going to reiterate them in writing. One of the things that CloudFlare is being brave about is looking at old code and deciding to rewrite it. Lots of companies live with legacy code and build on it and it eventuallybecomes a maintenance nightmare and slows the company down. Over the last year we've made major strides in rewriting parts of our code base so that they are faster, more maintainable, and easier to enhance. There are many parts of the Q3 roadmap that include replacing old parts of our stack. This is incredibly important as it enables us to be more agile and more stable in future. We should feel good Continue reading
