[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).Rapid Spanning Tree Synchronization – Keeping It Classless Labs
This is a specific video on Rapid Spanning Tree Synchronization. See my full writeup on RSTP in general. Forgive the low(er) quality of this particular video, it was recorded at an hour in the morning that frankly should not exist.[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. […]
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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. […]
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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 […]
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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 […]
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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 […]
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The post Speaker for the Dead – Telnet appeared first on Packet Pushers Podcast and was written by Steven Iveson.
Spanning Tree Nerd Knobs – Keeping It Classless Labs
This is a video on some of the “nerd knobs” that we get to play with in a traditional spanning tree environment. I have done a full writeup on the topic that goes along with this video - you can view this video on that page as well.[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).Spanning Tree Nerd Knobs – Keeping It Classless Labs
This is a video on some of the “nerd knobs” that we get to play with in a traditional spanning tree environment. I have done a full writeup on the topic that goes along with this video - you can view this video on that page as well.[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).Spanning Tree Nerd Knobs – Keeping It Classless Labs
This is a video on some of the “nerd knobs” that we get to play with in a traditional spanning tree environment. I have done a full writeup on the topic that goes along with this video - you can view this video on that page as well.[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:
- 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.
- 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.
- 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 […]
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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 […]
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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.
VIRL supports virtualizing Cisco’s modified operations system. Cisco Continue reading
Regarding scale-out network virtualization in the enterprise data center
There's been quite a lot of discussion regarding the benefits of scale-out network virtualization. In this blog I present some additional thoughts to ponder regarding the value of network virtualization in the enterprise DC. As with any technology options, the question that enterprise network operators need to ask themselves regarding scale-out network virtualization is whether it is the right solution to the problems they need to address.To know whether scale-out network virtualization in the enterprise DC is the answer to the problem, we need to understand the problem in a holistic sense. Let's set aside our desire to recreate the networks of the past (vlans, subnets, etc, etc) in a new virtual space, and with an open mind ask ourselves some basic questions.
Clearly at a high level, enterprises wish to reduce costs and increase business agility. To reduce costs it's pretty obvious that enterprises need to maximize asset utilization. But what specific changes should enterprise IT bring about to maximize asset utilization and bring about safe business agility? This question ought to be answered in the context of the full sum of changes to the IT model necessary to gain all the benefits of the scale-out Continue reading
How do I Justify this?
“Say I’m convinced that my company should choose one technology over another. How can I tell the whole truth, cover all the bases, explain all the alternatives, while making certain I make the case that the technology I’ve made, or would like to make, is the right one?” In case you’ve ever wondered what it’s […]
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The post How do I Justify this? appeared first on Packet Pushers Podcast and was written by Russ White.