RFC 3330 Filtering Using Network Objects

[Code] UltimateUCSBuild

Why We Want to Kill Spanning Tree

[Code] UltimateUCSBuild

Why We Want to Kill Spanning Tree

DCI: Using FabricPath for Interconnecting Data Centers

Here's a topic that comes up more and more now that FabricPath is getting more exposure and people are getting more familiar with the technology: Can FabricPath be used to interconnecting data centers?

For a primer on FabricPath, see my pervious article Five Functional Facts about FabricPath
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FabricPath has some characteristics that make it appealing for DCI. Namely, it extends Layer 2 domains while maintaining Layer 3 — ie, routing — semantics. End host MAC addresses are learned via a control plane, FP frames contain a Time To Live (TTL) field which purge looping packets from the network, and there are no such thing as blocked links — all links are forwarding and Equal Cost Multi-Pathing (ECMP) is used within the fabric. In addition, since FabricPath does not mandate a particular physical network topology, it can be used in spine/leaf architectures within the data center or point-to-point connections between data centers.

Sounds great. Now what are the caveats?

PQ Show 24 – Cisco OTV Deep Dive Part 1

New voices gather in the Packet Pushers virtual boardroom for a discussion of Cisco’s layer 2 extension technology, Overlay Transport Virtualization (OTV). Ethan Banks hosts a recording of about two hours worth of content about OTV; this show is the first hour. Joining Ethan are first-time guests Jamie Caesar, Colby Glass and Ken Matlock. Jamie, […]

Author information

Ethan Banks

Co-host at Packet Pushers

Ethan Banks, CCIE #20655, has been managing networks for higher ed, government, financials and high tech since 1995. Ethan co-hosts the Packet Pushers Podcast, which has seen over 3M downloads and reaches over 10K listeners. With whatever time is left, Ethan writes for fun & profit, studies for certifications, and enjoys science fiction. @ecbanks

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The post PQ Show 24 – Cisco OTV Deep Dive Part 1 appeared first on Packet Pushers Podcast and was written by Ethan Banks.

Have Respect For The Work You Do

The other day I was called in to assist with issue that had been open for a few days. The primary reason for my involvement was to confirm network connectivity was permitted as required by a recently installed application. After an initial look, it was apparent that the application wasn’t even trying to access network […]

Author information

Paul Stewart

Paul is a Network and Security Engineer, Trainer and Blogger who enjoys understanding how things really work. With nearly 15 years of experience in the technology industry, Paul has helped many organizations build, maintain and secure their networks and systems. Paul also writes technical content at PacketU.

The post Have Respect For The Work You Do appeared first on Packet Pushers Podcast and was written by Paul Stewart.

Are Forensics Tools the New IDS?

For the past few years, many people have been suggesting that the days of IDS (intrusion detection system) are numbered. When IDS was first launched, it was seen as an answer to a lot of network security problems: deep packet inspection with constant monitoring and alerts. However, one of the biggest problems with IDS is […]

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Darragh Delaney

Technical Director at NetFort

Darragh Delaney is head of technical services at NetFort. As Director of Technical Services and Customer Support, he interacts on a daily basis with NetFort customers and is responsible for the delivery of a high quality technical and customer support service.

Darragh has extensive experience in the IT industry, having previously worked for O2 and Tyco. His User and Network Forensics blog. for Computer World focuses his experiences of network management and IT security in the real world. In his current role Darragh is regularly on site with network administrators and managers and this blog is a window into the real world of keeping networks running and data assets secure.

He shares network security and management best practices on the NetFort blog. Follow Darragh on Twitter @darraghdelaney and NetFort Technologies @netfort. You can also contact him Continue reading

Monitoring VRFs on IOS-XR

Lately I have been investigating how to monitor BGP peering session via SNMP instead of traps/syslog messages and I found out that this feature is not documented properly for IOS XR. Finally I managed to get it working, so I thought that it would be worth sharing with the community. In our example, we have […]

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David Barroso

Networking Engineer focused mainly in the DataCenter. As an engineer at a large ISP he has to deal with large multitenant networks, DataCenter Interconnections, large MSTP regions, BGP and all that stuff that's scary to normal people.

Linkedin: http://www.linkedin.com/in/dbarrosop
Twitter: @dbarrosop

The post Monitoring VRFs on IOS-XR appeared first on Packet Pushers Podcast and was written by David Barroso.

Centec V330: My Kind of OpenFlow Switch

This is my third and probably last installment of an ongoing story about our quest for OpenFlow 1.0 capable switches with a specific requirement - the capability to modify L3 destination addresses. The background of why Sakura Internet needs such switches for the purpose of DDoS attack mitigation is explained in my first article, along with […]

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Tamihiro Yuzawa

Tamihiro Yuzawa is a network engineer at Sakura Internet, one of Japan's major data center service providers. Before he joined Sakura in 2007, he spent five years at a busy CRM service provider. Both companies have allowed him to stay mostly within the intersection of these circles, and he is pretty much determined to remain in a serious relationship with both Dev and Ops.

The post Centec V330: My Kind of OpenFlow Switch appeared first on Packet Pushers Podcast and was written by Tamihiro Yuzawa.

Adding Markdown support to your WordPress Blog

Continuning on this week's theme of Markdown, I'll be explaining how to add Markdown to your blog in 3 easy steps.

Adding Markdown support to your WordPress Blog

Continuning on this week's theme of Markdown, I'll be explaining how to add Markdown to your blog in 3 easy steps.

Step 1 - Install the WP-Markdown plugin

From your Wordpress dashboard, head over to the Plugins tab and click Add New. Search for "WP-Markdown" and install

Step 2 - Enable Markdown for specific pages

Once your plugin has been installed, head on down to Settings > Writing and scroll to the Markdown section pictured below.

Enable Markdown wherever you like, but I'd recommend pages and posts

WARNING: Enabling Markdown will affect your existing posts/pages. I noticed that while my posts didn't look any different on the outside, behind the scenes they were a mess and required a little trying up.

Step 3 - Try it out

Create a new post or page and practice your Markdown-Fu. Not sure where to start? Here's an example

# This is a first level heading

Here is some body text

## Second level of heading here
### And a Third
#### And so on and so forth

- Now some bullets
- Hopefully you are getting the hang of this now
- It's pretty easy

> Blockquotes are easy with Markdown  Continue reading

Adding Markdown support to your WordPress Blog

Continuing on this week's theme of Markdown, I'll be explaining how to add Markdown to your blog in 3 easy steps.

Cisco UCS ASCII Art

[Code] PowerTool: PowerOnUCSBlades

[Code] PowerTool: PowerOnUCSBlades

Cisco UCS ASCII Art

Why I switched from MultiMarkdown to Pandoc

For the last 6 months I've been using Markdown where I can. Since embarking on the path towards a more Agile approach to writing, it has been necessary to use Markdown more and more. This has led me towards using Pandoc Markdown rather than MultMarkdown as my dialect of choice and I hope to explain why.

Why I switched from MultiMarkdown to Pandoc

For the last 6 months I've been using Markdown where I can. Since embarking on the path towards a more Agile approach to writing, it has been necessary to use Markdown more and more. This has led me towards using Pandoc Markdown rather than MultMarkdown as my dialect of choice and I hope to explain why.

So what's so good about Markdown?

If you haven't used Markdown already, you might be wondering what the fuss is about. Basically it is a way of writing markup in an easy-to-read, easy-to-write fashion. It decouples the act of writing from formatting/layout so the same source text can be used to produce multiple formats.

Barriers to Markdown adoption

So what are the barriers to Markdown adoption? Personally I have found only two.

While I use Markdown, the rest of the company uses Microsoft Word - All of our corporate templates are in MS Word format - Neither Markdown or MultiMarkdown reliably export to MS Word format (yes MMD does ODF, but it doesn't handle images well)

The next issue is that Markdown to PDF conversion uses LaTeX. Unfortunately I neither have the time nor inclination to learn LaTeX. While it can be a powerful Continue reading