Category: data center

The next session of the Network Automation Use Cases series will take place on January 24th. Dinesh Dutt will explain describe how you can use Ansible and Jinja2 to automate data center fabric deployments, and I’ll have a few things to say about automating network security.

If you think that what Dinesh will talk about applies only to startups you’re totally wrong. UBS is using the exact same approach to roll out their new data centers; Thomas Wacker will share the details in his guest presentation in the next Building Next-Generation Data Centers online course.

I rarely get OpenFlow questions these days; here’s one I got not so long ago:

I've just spent the last 2 days of my life consuming the ONF 1.3.3 white paper in addition to the $vendor SDN guide to try and reconcile what features it does or does not support and have come away disappointed...

You’re not the only one ;)

One of my readers designing a new data center fabric that has to provide L2 transport across the data center sent me this observation:

While we don’t have plans to seek an open solution in our DC we are considering ACI or VXLAN with EVPN. Our systems integrator partner expressed a view that VXLAN is still very new. Would you share that view?

Assuming he wants to stay with Cisco, what are the other options?

Dinesh Dutt was the guest speaker in the second Leaf-and-Spine Fabric Design session. After I explained how you can use ARP/ND information to build a layer-3-only data center fabric that still supports IP address mobility Dinesh described the details of Cumulus Linux redistribute ARP functionality and demoed how it works in a live data center.

Got this comment to one of my L2-over-VXLAN blog posts:

I found the Avaya SPBM solution "right on the money" to build that L2+ fabric. Would you deploy Avaya SPBM?

Interestingly, I got that same question during one of the ExpertExpress engagements and here’s what I told that customer:

One of my readers was watching the Building Active-Active Data Centers webinar and sent me this question:

I’m wondering if you have additional info on how to address the ingress traffic flow issue? The egress is well explained but the ingress issue wasn’t as well explained.

There’s a reason for that: there’s no good answer.

Got this set of questions from one of my readers:

I just met up with DELL guys for Big Switch SDN. They claim there is no routing running on leaf switches, the BCF is purely OpenFlow.

Almost true. It is based on OpenFlow, but they use tons of their own OpenFlow extensions to get stuff to work. That’s also why you have to install their agent on the switches.

After introducing the fundamentals of Docker networking, Dinesh Dutt focused on various Docker networking options, including multi-host networking with overlays.

After watching the video, you might also want to listen to Episode 49 of Software Gone Wild with Brent Salisbury, Dave Tucker and Madhu Venugopal.

A while ago I wrote:

I haven’t seen any hard data, but intuition suggests that apart from hardware failures a standalone firewall might be more stable than a state-sharing firewall cluster.

Guillaume Sachot (working for a web hosting company) sent me his first-hand experience on this topic:

One of my readers sent me an interesting question a while ago:

Isn’t IS-IS a better fit for building L3-only networks than BGP, particularly considering that IS-IS already has a protocol to communicate with the end systems (ES-IS)?

In theory, he’s correct (see also this blog post).

Our Data Center optimization journey has finished. We virtualized the workload, got rid of legacy technologies, reduced the number of server uplinks, replaced storage arrays with distributed file system and replaced physical firewalls and load balancers with virtual appliances.

Let’s see what’s left: it turns out you really don’t need more than two switches in most data centers.

It’s only two weeks since the last live session of the Autumn 2016 Data Center course in which Mitja Robas did a fantastic job describing a production deployment of VMware NSX on top of Cisco Nexus 9000 network, and we already have the first speakers for the Spring 2017 event:

• Scott Lowe (now at VMware) will talk about the role of open source in data center infrastructure;
• Thomas Wacker (UBS AG) will talk about their fully automated data center deployments;
• Andrew Lerner and Simon Richard (Gartner) will participate in a panel discussion on data center and networking trends.

Continuing the Do Enterprises Need VRFs discussion, let’s see which enterprise networks might need MPLS.

Do you need VRFs?

Read the previous blog post. If the answer is NO, you can stop reading. Otherwise, carry on.

Do you need large buffers in data center switches or not? If you’re a vendor your take obviously depends on whether you have them or not, and then there are people saying “it’s bullshit” (mostly agree) and “look, I have a shinier toy” (get lost).

Unfortunately, it’s really hard to get someone who would know what he’s talking about, and be relatively unbiased.

One of my readers sent me this question:

Using SSL over the Internet is a must when dealing with sensitive data. What about SSL between data center components (frontend load-balancers and backend web servers for example)? Does it make sense to you? Can the question be summarized as "do I trust my Datacenter network team"? Or is there more at stake?

In the ideal world in which you’d have a totally reliable transport infrastructure the answer would be “There’s no need for SSL across that infrastructure”.