[Quality of Service] Part 3 – Nexus 1000v: The Servers are Doing QoS Now?!?
I’m going to talk a little bit about performing QoS functions from within the Nexus 1000v. Since it’s been awhile since I made the last post in this series, a recap is in order: In my first post, I explained what the different types of QoS policies were in the context of Cisco’s MQC In my second post, I went through the actual configuration on specific platforms like the Cisco Nexus and Unified Compute platforms, as well as a brief mention of vSphere’s participation, but less on the QoS aspects and more on MTU.[Humor] Virtual Routing Inception
Don’t ask me what kind of daydreaming it took to arrive at this, but….I just realized that the following was possible: Which was ALREADY terrifying enough - but then my mind went here: Have a great weekend.Identifying Introverted Tendencies
It’s no secret that our industry is full of those with interesting eccentricities. These characteristics are found in varying degrees with those we come into contact with daily. The extremes of these often manifest themselves as a general perception of those in technology. This even happens as technical characters are portrayed television. One example of this […]
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The post Identifying Introverted Tendencies appeared first on Packet Pushers Podcast and was written by Paul Stewart.
Open Source Switching
There’s been a ton of attention lately around the concept of using commodity hardware in an area of the industry that is currently dominated by proprietary ASIC-based solutions - networking. When it comes to crossing paths between open source and networking, the obvious low-hanging fruit has been software-based switching solutions like Open vSwitch, or cool ways to make virtual switching do bigger, better stuff for cloud providers like Openstack Quantum (awesome, by the way).Open Source Switching
There’s been a ton of attention lately around the concept of using commodity hardware in an area of the industry that is currently dominated by proprietary ASIC-based solutions - networking. When it comes to crossing paths between open source and networking, the obvious low-hanging fruit has been software-based switching solutions like Open vSwitch, or cool ways to make virtual switching do bigger, better stuff for cloud providers like Openstack Quantum (awesome, by the way).Book Review: A Primer of Multicast Routing
I was recently in need of a refresher on multicast routing, so I picked up Eric Rosenberg’s A Primer of Multicast Routing (Springer Briefs in Computer Science). The overall plan of the book is excellent, starting with a basic overview of what multicast is (and does), including why multicast is more efficient than unicast for […]
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The post Book Review: A Primer of Multicast Routing appeared first on Packet Pushers Podcast and was written by Russ White.
What is static floating route
How does the internet work - We know what is networking
Static floating route is static route like any other but with added administrative distance in the configuration R1(config)#ip route 172.16.10.0 255.255.255.0 10.10.10.2 200 Defining the packets route using Static Floating Routes is very interesting topic so I decided to give you a short description of Static floating routes with an example. Static floating route is the […]
How to Turn Your IOS Router Into a Pr0n Server (Pr0n Not Included)
No, really! Did you know that your IOS-based router is capable as acting as a static webserver? Below you will find the steps necessary to turn a GNS/Dynamips box (or any ‘testlab’ machine) into something that can serve basic HTTP/HTTPS content. Due to the security implications of the steps below, it’s not recommended to do […]
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The post How to Turn Your IOS Router Into a Pr0n Server (Pr0n Not Included) appeared first on Packet Pushers Podcast and was written by Ken Matlock.
[Virtual Routing] Part 3 – Router Redundancy in VMware vSphere
My post a few weeks ago about the CSR 1000v made a pretty big splash - it’s clear that the industry is giving a lot of attention to IP routing within a virtual environment. No doubt, Vyatta is largely credited for this, as they’ve been pushing this idea for a long time. When Brocade announced that they were acquiring Vyatta, and Cisco announced they were working on a “Cloud Services Router”, this idea became all the more legitimate, and as you can tell from this series, it’s of particular interest to me.[Virtual Routing] Part 3 – Router Redundancy in VMware vSphere
My post a few weeks ago about the CSR 1000v made a pretty big splash - it’s clear that the industry is giving a lot of attention to IP routing within a virtual environment. No doubt, Vyatta is largely credited for this, as they’ve been pushing this idea for a long time. When Brocade announced that they were acquiring Vyatta, and Cisco announced they were working on a “Cloud Services Router”, this idea became all the more legitimate, and as you can tell from this series, it’s of particular interest to me.[Virtual Routing] Part 3 – Router Redundancy in VMware vSphere
My post a few weeks ago about the CSR 1000v made a pretty big splash - it’s clear that the industry is giving a lot of attention to IP routing within a virtual environment. No doubt, Vyatta is largely credited for this, as they’ve been pushing this idea for a long time. When Brocade announced that they were acquiring Vyatta, and Cisco announced they were working on a “Cloud Services Router”, this idea became all the more legitimate, and as you can tell from this series, it’s of particular interest to me.Show 146 – Arista 7500 – One Switch to Rule Them All – Sponsored
Arista is shipping a serious round of upgrades for the 7500 switch chassis. In this sponsored podcast, Doug Gourlay from Arista returns to the Packet Pushers to give an unvarnished view of the new products and why Arista can deliver 100GbE at a new price point while maintaining technical features and capabilities. Show Topics: 1) It’s […]
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The post Show 146 – Arista 7500 – One Switch to Rule Them All – Sponsored appeared first on Packet Pushers Podcast and was written by Greg Ferro.
Convert Hex to Decimal in IOS
Lots of IOS commands produce output in hex that I sometimes want to convert to decimal. Common ones for me are stuff like:show ip cache flow
show ip flow top-talkers
and various debug commands. For example:
Router#sh ip cache flow | i Fa1/0.6
Fa0/1.6 10.5.188.158 Tu101* 10.5.24.15 06 0DA7 6D61 345
I have no idea what the port numbers in columns six and seven are. Fortunately, if the IOS device has the TCL or Bash shells available, we can quickly convert them.
Method 1: Tcl Shell
Most routers have the Tcl shell available:Router#tclsh
Router(tcl)#puts [expr 0xda7]
3495
Router(tcl)#puts [expr 0x6d61]
28001
You could write a callable Tcl script to make this permanently available from normal EXEC mode too.
Method 2: Bash Shell
The Bash shell came out in one of the early IOS 15.0 versions, so you may or may not have it available. You need to explicitly enable it by entering "shell processing full" in global configuration mode.Router#sh run | i shell
shell processing full < required to enable Bash in IOS 15+
Router#printf "%d" 0xda7
3495
Router#printf "%d" 0x6d61
28001
Getting the Most Out of SPAN or Mirror Ports
In my previous blog post I looked at the benefits and limitations of SPAN ports. SPAN or mirror ports are a convenient way of getting access to network packets without having to be inline like a firewall. Once you have got your network packet source in place, the next question is, what applications are available […]
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SDN Use Case: End-to-End QoS
Just a little unicorn-y brainstorming today. This post is in some ways an extension of my earlier post on the importance of QoS in a converged environment like FCoE or VoIP (or both). This will be a good example of a case where SDN very efficiently solves a policy problem that is present in an unfortunately large number of networks today. For many organizations, large or small, the network is approached with a very siloed, “good enough” mentality - meaning that each portion of an organization’s technology implementation is typically allocated to those that have that particular skillset.SDN Use Case: End-to-End QoS
Just a little unicorn-y brainstorming today. This post is in some ways an extension of my earlier post on the importance of QoS in a converged environment like FCoE or VoIP (or both). This will be a good example of a case where SDN very efficiently solves a policy problem that is present in an unfortunately large number of networks today. For many organizations, large or small, the network is approached with a very siloed, “good enough” mentality - meaning that each portion of an organization’s technology implementation is typically allocated to those that have that particular skillset.Patent filed
Finally, I have finished to file my patent regrading PVTD - The Private VLAN enabler. It is storage how a patent attorney is able to add so many words to a technical document which he has got very limited understanding of its content… Anyway, I am back to authoring labs.Are You a Fuddy Duddy?
This recent article from IEEE Spectrum discusses our impression that as we age, we lose the ability to learn quickly — fluid intelligence, as it’s called. An accompanying chart shows this in some degree through the skill of chess players across a range of ages. There’s something suspicious about this chart, though, and it’s pairing […]
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The post Are You a Fuddy Duddy? appeared first on Packet Pushers Podcast and was written by Russ White.
What is Jitter in Networking?
How does the internet work - We know what is networking
Simply said, time difference in packet inter-arrival time to their destination can be called jitter. Jitter is specific issue that normally exists in packet networks and this phenomenon is usually not causing any communication problems. TCP/IP is responsible for dealing with the jitter impact on communication. On the other hand, in VoIP network environment, or better […]
Machine Fragile: More Thoughts
I just ran across a pointer to this research on Bruce Schneier’s blog: Networking system components that are well-behaved in separation may create counter-intuitive emergent system behaviors, which are not well-behaved at all. For example, cooperative behavior might unexpectedly break down as the connectivity of interaction partners grows. “Applying this to the global network of […]
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The post Machine Fragile: More Thoughts appeared first on Packet Pushers Podcast and was written by Russ White.