Interview with Daniel Dib

Daniel Dib is setting up a networking career (from a down-to-earth engineer’s perspective) web site, and started populating it with numerous interviews with fellow networking engineers and architects (all of them well worth reading).

Here are my answers to his questions.

RFC 8212: Bringing Sane Defaults to EBGP

It’s amazing how long it can take to get some sanity into networking technologies. RFC 8212 specifies that a BGP router should not announce prefixes over EBGP until its routing policy has been explicitly configured. It took us only 22 years to get there…

For more technical details, read this email by Job Snijders.

Net Neutrality (Again and Again and Again)

Net neutrality is one of those topics that should never have existed, but of course it inevitably erupts every so often, so here we go…

Not so long ago Robert Graham published his anti-net-neutrality arguments which are (no surprise) not much different from what I wrote when I still cared about this argument (here, here, here and here). While I agree with his overall perspective, I completely disagree with his view of Comcast’s initial response to network congestion.

RFC8200: IPv6 Is an Internet Standard

You wouldn’t believe it – after almost 22 years (yeah, it’s been that long since RFC 1883 was published), IPv6 became an Internet standard (RFC8200/STD86). No wonder some people claim IETF moves at glacial speed ;)

Speaking of IPv6, IETF and glacial speeds – there’s been a hilarious thread before Prague IETF meeting heatedly arguing whether the default WLAN SSID should be IPv6-only (+NAT64). Definitely worth reading (for the entertainment value) over a beer or two.

New in Ansible for Networking Engineers

I’ve added two new case studies to Ansible for Networking Engineers online course:

Create network diagrams from LLDP information playbook focuses on creating a single summary report based on information from numerous devices (and the report just happens to be network diagram in DOT format).

PRTG Monitoring Software Now Available in Cloud Version

One of the more interesting presentations we had during Tech Field Day Extra @ Cisco Live Berlin was coming from Paessler, a company developing PRTG, a little-known network monitoring software.

More about PRTG in TFD videos and here, here, here and here.

RFC 8196: IS-IS Autoconfiguration

Finally a group of engineers figured out it’s a good idea to make things less complex instead of heaping layers of complexity on top of already-complex kludges.

RFC 8196 specifies default values and extensions to IS-IS that make it a true plug-and-play routing protocol. I wonder when we’ll see it implemented now that everyone is obsessed with intent-based hype.

Promises Gone Wild

I got several interesting replies to my automation and orchestration blog post. Some of them were so far in the land of alternate definitions that they were literally off the charts. Here’s one of the best I got in that category:

(Not-so-very) Early Network Automation

If you’re not old enough to know otherwise, you’d think (based on recent hype) that we discovered network automation a few years ago. Not true. One of my readers sent me a link to excellent Managing IP Networks with Free Software presentation from NANOG26 (October 2002).

I found the presentation awesome, nothing new, and extremely sad… all at the same time.

IPv6 Link-Local Addresses and VLAN Interfaces

One of my readers sent me an email that’s easiest paraphrased into: “Why can’t I have a different IPv6 link-local address (LLA) on every access port connected to a VLAN interface?”

There’s probably nothing stopping someone from implementing such an approach, but it would go against the usual understanding of how bridging and routing interact in L2+L3 switches.

Q&A: Building Network Automation Solutions Online Course

I got tons of questions about the upcoming Building Network Automation Solutions online course. It always starts with the same one:

Is access to the self-study material granted upon enrollment?

Absolutely. You also get access to everything we did in January, and the new self-paced Ansible for Networking Engineers online course.

Automation or Orchestration?

Have you ever wondered what the difference between automation and orchestration is?

Wikipedia defines automation as use of various control systems for operating equipment. The definition I prefer (because it’s easier to understand in network automation environment) is elimination of well-defined repeatable manual tasks – the emphasis being on well-defined and repeatable.

Swimlanes, Read-Write Transactions and Session State

Another question from someone watching my Designing Active-Active and Disaster Recovery Data Centers webinar (you know, the one where I tell people how to avoid the world-spanning-layer-2 madness):

In the video about parallel application stacks (swimlanes) you mentioned that one of the options for using the R/W database in Datacenter A if the user traffic landed in Datacenter B in which the replica of the database is read-only was to redirect the user browser with the purpose that the follow up HTTP POST land in Datacenter A.

Here’s the diagram he’s referring to:

New in Ansible for Networking Engineers

Here’s the list of materials (and other changes) I added to the Ansible for Networking Engineers webinar and online course in June 2017.

The first thing you’ll notice is the brand-new user interface with collapsible sections, making it easier to grasp the big picture (the change was badly needed – the webinar is already almost 12 hours long).

Breaking News: SNMP-based NMS Can Replace SDN ;)

Got this remark from one of my SDN mailing list subscribers:

There are NMSs that are based on SNMP, their manufacturers that say they can replace an SDN architecture, because they allow to automate the management of the network.

O’RLY?

How Do I Start Automating Network Device Configurations in an Existing Network?

I get a “how do I get started with network automation” question every other week, and when I wrote a lengthy reply to one about configuration templating of existing snowflake network on networktocode Slack channel I decided it’s time to turn my replies into a blog post.

To Jumbo or Not to Jumbo?

Here’s the question I got from one of my readers:

Do you have any data available to show the benefits of jumbo frames in 40GE/100GE networks?

In case you’re wondering why he went down this path, here’s the underlying problem:

Solutions Published for Wireshark Challenges

Johannes Weber published the solutions to his Wireshark challenges. How many did you solve?

Sample Network Automation Ansible Playbooks

I developed over a dozen different Ansible-based network automation solutions in the last two years for my network automation workshops and online course, and always published them on GitHub… but never built an index, or explained what they do, and why I decided to do things that way.

With the new my.ipSpace.net functionality I added for online courses I got the hooks I needed to make the first part happen:

Asymmetrical Traffic Flows and Complexity

One of my readers sent me a list of questions on asymmetrical traffic flows in IP networks, particularly in heavily meshed environments (where it’s really hard to ensure both directions use the same path) and in combination with stateful devices (firewalls in particular) in the forwarding path.

Unfortunately, there’s no silver bullet (and the more I think about this problem, the more I feel it’s not worth solving).