[CCIE] Spanning-Tree Part 2 – RSTP

This post picks up where the previous left off. Again, a CCNP-level knowledge of STP is recommended. So…Spanning Tree didn’t converge quickly enough for some people, and enabling PortFast everywhere kind of defeats the purpose, so 802.1w Rapid Spanning Tree was born. RSTP in essence puts into place some additional features to speed up STP reconvergence. Old-school 802.1D meant that you had to wait at least 30 seconds to get a port from blocking to forwarding, and this means that recovering from a failure takes at least that much time (sometimes more depending on other factors).

[CCIE] Spanning-Tree Part 2 – RSTP

This post picks up where the previous left off. Again, a CCNP-level knowledge of STP is recommended. So…Spanning Tree didn’t converge quickly enough for some people, and enabling PortFast everywhere kind of defeats the purpose, so 802.1w Rapid Spanning Tree was born. RSTP in essence puts into place some additional features to speed up STP reconvergence. Old-school 802.1D meant that you had to wait at least 30 seconds to get a port from blocking to forwarding, and this means that recovering from a failure takes at least that much time (sometimes more depending on other factors).

Masterclass – Tcpdump – Parameters

This Masterclass article series aimes to provide in-depth technical information on the installation, usage and operation of the classic and supremely popular tcpdump network traffic analysis program including alternatives, running tcpdump as a process, building expressions, understanding output and more. I’ve covered the Basics previously, will cover Parameters here, then filter Expressions and finally Interpreting Output. […]

Author information

Steven Iveson

Steven Iveson

Steven Iveson, the last of four children of the seventies, was born in London and has never been too far from a shooting, bombing or riot. He's now grateful to live in a small town in East Yorkshire in the north east of England with his wife Sam and their four children.

He's worked in the IT industry for over 15 years in a variety of roles, predominantly in data centre environments. Working with switches and routers pretty much from the start he now also has a thirst for application delivery, SDN, virtualisation and related products and technologies. He's published a number of F5 Networks related books and is a regular contributor at DevCentral.

The post Masterclass – Tcpdump – Parameters appeared first on Packet Pushers Podcast and was written by Steven Iveson.

PQ Show 26 – Cisco Live Network, IPv6 and Hugs All Round – Sponsored

Guests Patrick Warichet Alain Fiocco @alainfiocco Andrew Yourtchenko @ayourtch Kumar Reddy @kumarreddy Show Notes You can follow the Cisco IPv6 Lab Team on Twitter at @cisco6lab “Happy Eyeballs” – RFC6555 – Happy Eyeballs: Success with Dual-Stack Hosts – http://tools.ietf.org/html/rfc6555 Test your IPv6 http://test-ipv6.com/ IPvFoo – https://code.google.com/p/ipvfoo/ 6lab.cisco.com/stats Sessions on Cisco Live 365 from Orlando, 2013. […]

Author information

Greg Ferro

Greg Ferro is a Network Engineer/Architect, mostly focussed on Data Centre, Security Infrastructure, and recently Virtualization. He has over 20 years in IT, in wide range of employers working as a freelance consultant including Finance, Service Providers and Online Companies. He is CCIE#6920 and has a few ideas about the world, but not enough to really count.

He is a host on the Packet Pushers Podcast, blogger at EtherealMind.com and on Twitter @etherealmind and Google Plus.

The post PQ Show 26 – Cisco Live Network, IPv6 and Hugs All Round – Sponsored appeared first on Packet Pushers Podcast and was written by Greg Ferro.

Show 151 – Defining Software Defined Whatever

The hosts of the Speaking in Tech podcast join the Packet Pushers to discuss “not networking” just ahead of the Cisco Live conference. CLUS roving reporter Chris Wahl @chriswahl takes part in the melee. Dropping insults on ITIL and ITSM once again. Defining Software Defined Whatever because “My Other Software Defined is Your Mom” Software […]

Author information

Greg Ferro

Greg Ferro is a Network Engineer/Architect, mostly focussed on Data Centre, Security Infrastructure, and recently Virtualization. He has over 20 years in IT, in wide range of employers working as a freelance consultant including Finance, Service Providers and Online Companies. He is CCIE#6920 and has a few ideas about the world, but not enough to really count.

He is a host on the Packet Pushers Podcast, blogger at EtherealMind.com and on Twitter @etherealmind and Google Plus.

The post Show 151 – Defining Software Defined Whatever appeared first on Packet Pushers Podcast and was written by Greg Ferro.

Masterclass – Tcpdump – Basics

This Masterclass article series aimes to provide in-depth technical information on the installation, usage and operation of the classic and supremely popular tcpdump network traffic analysis program including alternatives, running tcpdump as a process, building expressions, understanding output and more. I’ll cover the Basics here and move on to Parameters, then filter Expressions and finally Interpreting […]

Author information

Steven Iveson

Steven Iveson

Steven Iveson, the last of four children of the seventies, was born in London and has never been too far from a shooting, bombing or riot. He's now grateful to live in a small town in East Yorkshire in the north east of England with his wife Sam and their four children.

He's worked in the IT industry for over 15 years in a variety of roles, predominantly in data centre environments. Working with switches and routers pretty much from the start he now also has a thirst for application delivery, SDN, virtualisation and related products and technologies. He's published a number of F5 Networks related books and is a regular contributor at DevCentral.

The post Masterclass – Tcpdump – Basics appeared first on Packet Pushers Podcast and was written by Steven Iveson.

Speaker for the Dead – Telnet

The idea of this article series is for me to play the part of a ‘Speaker for the Dead’ for technology that has or is becoming ‘end of life’ or legacy and/or irrelevant (or which should be). In this article, I’ll cover Telnet; the good, the bad, the ugly, the full (but brief) and honest […]

Author information

Steven Iveson

Steven Iveson

Steven Iveson, the last of four children of the seventies, was born in London and has never been too far from a shooting, bombing or riot. He's now grateful to live in a small town in East Yorkshire in the north east of England with his wife Sam and their four children.

He's worked in the IT industry for over 15 years in a variety of roles, predominantly in data centre environments. Working with switches and routers pretty much from the start he now also has a thirst for application delivery, SDN, virtualisation and related products and technologies. He's published a number of F5 Networks related books and is a regular contributor at DevCentral.

The post Speaker for the Dead – Telnet appeared first on Packet Pushers Podcast and was written by Steven Iveson.

[CCIE] Spanning-Tree Part 1 – Nerd Knobs

I wrote this post not only to put out some information on one of the least-understood facets of networking (especially in data center, as most technology today is aimed at making STP irrelevant) but also to help get something on paper for me, seeing as I am going down the CCIE path full force now, and this has always been a weak area of mine. This post will assume you have CCNP-level knowledge about Spanning Tree Protocol (STP).

[CCIE] Spanning-Tree Part 1 – Nerd Knobs

I wrote this post not only to put out some information on one of the least-understood facets of networking (especially in data center, as most technology today is aimed at making STP irrelevant) but also to help get something on paper for me, seeing as I am going down the CCIE path full force now, and this has always been a weak area of mine. This post will assume you have CCNP-level knowledge about Spanning Tree Protocol (STP).

[CCIE] Spanning-Tree Part 1 – Nerd Knobs

I wrote this post not only to put out some information on one of the least-understood facets of networking (especially in data center, as most technology today is aimed at making STP irrelevant) but also to help get something on paper for me, seeing as I am going down the CCIE path full force now, and this has always been a weak area of mine. This post will assume you have CCNP-level knowledge about Spanning Tree Protocol (STP).

All Aboard the Application Train!

It’s been an interesting week so far… and it’s only Wednesday. In just a little over a day and a half, we’ve had hundreds of people stop by our booth at Cisco Live! and I wanted to share a few observations from those interactions:

  1. A significant number of people still do not know or understand much about SDN. This isn’t surprising and further underscores the disservice vendors have done at creating confusion that I wrote about a couple of weeks ago.
  2. When you talk about an application-centric approach to networking and network service automation, people get interested very fast, even when they are not building or using a cloud.
  3. Everyone is asking for examples of real use cases and deployments to help them determine which vendors they should engage/invest their time.

I suppose I shouldn’t be too surprised that networkers aren’t that familiar with software. Given that Cisco is talking a little more about software and software-defined networking these days, that’ll probably change by this time next year. In fact, Cisco spent much of Wednesday morning outlining its “vision” for application-centric infrastructure. From my perspective it’s a great thing to have Cisco promote the concept we’ve been pushing for a Continue reading

Speaker for the Dead – Spanning Tree Protocol

A friend of mine* text me early last week asking if I wanted to go to the cinema and watch the film After Earth. I couldn’t/wouldn’t go as I’m still up to my neck in book writing, but I thought I’d distract myself for a minute or two and read a few reviews of the […]

Author information

Steven Iveson

Steven Iveson

Steven Iveson, the last of four children of the seventies, was born in London and has never been too far from a shooting, bombing or riot. He's now grateful to live in a small town in East Yorkshire in the north east of England with his wife Sam and their four children.

He's worked in the IT industry for over 15 years in a variety of roles, predominantly in data centre environments. Working with switches and routers pretty much from the start he now also has a thirst for application delivery, SDN, virtualisation and related products and technologies. He's published a number of F5 Networks related books and is a regular contributor at DevCentral.

The post Speaker for the Dead – Spanning Tree Protocol appeared first on Packet Pushers Podcast and was written by Steven Iveson.

Networking Learning Paths – Route/Switch or Speciality Knowledge?

I spent the first ten years of my career in mobile telecoms. I learned a ton of lessons and I really enjoyed it, but I’ve always been drawn to networking. However I wasn’t getting hands-on exposure to data networks in my telco job so I had to teach myself. In 2002 I began the transition […]

Author information

John Harrington

John is an experienced data center engineer with a background in mobile telecoms. He works as a network test engineer for a large cloud service provider, and is gradually accepting that he's a nerd. He blogs about network technology and careers at theNetworkSherpa.com. You can reach him on twitter at: @networksherpa

The post Networking Learning Paths – Route/Switch or Speciality Knowledge? appeared first on Packet Pushers Podcast and was written by John Harrington.

VIRL – Why you need to know about it!

At Cisco Live in Orlando I had the chance to demo the Virtual Internet Routing Lab (VIRL). It is Cisco’s answer to GNS3 or Junipers’ Junosphere using virtualization to create virtual network topologies. This tools will be as revolutionary as GNS3, but at a much larger scale. It is an awesome tool that can be used for certification studying but also to validate production designs. Everyone I spoke to couldn’t wait to get their hands on it, including me!

Below is a screen shot of VIRL. It is using Oracles VMMaestro GUI based on Java. In the screen you can see network topology which is drop and drag. On the left side in purple there is a list of all saved networks. The right middle side has a list of supported devices. Top right side has all of the currently running devices and bottom right preconfiguration tabs. To access CLI of these routers, you has to run in simulation mode then Telnet to individual devices. The preconfiguration is a nice feature that allows you preconfigure IP addresses, Loopback interfaces or routing protocols like OSPF or BGP.

Virtual Internet Routing Laboratory screen shot.

Virtual Internet Routing Laboratory screen shot.

VIRL supports virtualizing Cisco’s modified operations system. Cisco Continue reading