I’ve been building networks for nearly thirty years. I understand leaf-spine fabrics, BGP design, VRF isolation, ECMP, and congestion management. I’ve designed data centers for financial institutions where microseconds mattered and ISP backbones where five nines was the floor.
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Networking Field Day 40 – Back at it again
I’m Heading to Networking Field Day 40 I’m excited to announce that I’ve been selected as a delegate for Networking Field Day 40, taking place April 8–10, 2026 in Silicon Valley.
Stop using 192.168.1.0/24: A Contrarian Guide to Home Network Addressing
If you’re a contractor, consultant, or anyone who VPNs into multiple client networks, you’ve experienced the pain.
Debating SSL Decryption in 2024
Yet another day brings another meeting about another security product recommending SSL Decryption at our network edge.
Engineering a Better Blog: Our Move to Hugo
Routerjockey has transitioned to Hugo, a fast and flexible static site generator.
Cisco Viptela drops the ball
In 2012, we saw the launch of Viptela, a pioneer in SDWAN network solutions.
Will 2023 be the year of Artificial Intelligence for InfoSec?
Gartner has been saying that “next big thing” in network security is the increased use of artificial intelligence (AI) and machine learning (ML) technologies for years now… Mainly …
Introducing Graphiant: The Future of Network-as-a-Service
As businesses continue to shift towards remote and distributed work environments, the need for secure and reliable network infrastructure has never been greater.
Mandatory Cisco DNA Licensing – is this the Future??
With the release of the new 9200 series switches many enterprise organizations are starting to look towards the future.
AIOps the next big thing for Enterprise IT?
But how does all of this relate to IT Infrastructure and Operations? AIOps is the combination of AI and IT Operations.
Gartner – more than a magic quadrant
In the past I have personally given a lot of flack towards Gartner, but that was when I was in a different stage of my career.
PCAP PCAP PCAP – Changes to RJ Store
I made a couple changes to the RouterJockey store this week and I wanted to make sure I got the word out.
IP Infusion powering the world from behind the scenes
Founded by Kunihiro Ishiguro and Yoshinari Yoshikawa the founders of GNU Zebra, came together to form IP Infusion back in 1999 as a commercial-grade, hardware-independent …
VMware NSX is something something awesome
At times I have trouble focusing on writing articles for some of the presentations I am exposed to at Tech Field Day. Because of that, I really wanted to try something different.
PCAP t-shirts just in time for CLUS17
Hey guys, I just wanted to drop a quick note to let you know that I’ve relaunched my teespring shirt campaigns with enough time that you should get your orders before Cisco Live US …
PNDA provides scalable and reactive network analytics
During Networking Field Day 15 our friends from the Linux Foundation, including Lisa Caywood, briefed us on a recent “acquisition” from Cisco.
Networking Field Day 15 – A new delegate emerges
Yet again I find myself honored, and questioning their selection methods, by being selected for a Networking Field Day event.
Ixia Vision ONE – Tap the Planet
Whenever I start talking about network visibility and aggreagation taps I can’t help but think of The Matrix.
Forward Networks – A forward approach to formal verification
Forward Networks has stepped out of the shadows to announce their Network Assurance platform, and I was fortunate enough to be a delegate for Networking Field Day 13 to see their …
Intel Atom SoC bricking more than Cisco products
Looks like the culprit in the recent Cisco debacle is the Intel Atom “System on Chip” (SoC) that Cisco used in it’s gear.
Cisco goes public with Clock Signal Component Issue
A couple months ago many engineers started hearing rumors regarding an ISR 4331 recall, and problems surrounding the device.
Networking Field Day 13 – Sneak Preview
This is going to be a busy week for the Tech Field Day family.
5 important reasons you should learn scripting
Today’s IT landscape if full of software defined marketecture, and lore of a dystopian future full of network engineers that do nothing but write code.
The complexity required for robustness, often goes against robustness
In the past few months we have seen major outages from United Airlines, the NYSE, and the Wall Street Journal.
Site Upgrades for September 2015
First, I want to apologize for not doing my job. Over the past couple years I’ve let this site become slightly stagnant.
RouterJockey is launching a clothing line?!?!???
Ok maybe that title is a bit grandiose… But due to the great response I received Friday morning from the launch of the original PCAP shirt, and the IPv6 follow-up, I decided to …
PCAP or it didn’t happen…. The t-shirt!
Some days I don’t know why I do things… But last night I was playing around with creating a PCAP meme when my friend Josh Kittle said he’d be interested in a t-shirt like that.
ASA v9.4 Elliptic Curve Cryptography with TLS1.2
With ASA version 9.4 Cisco has added support for Elliptic curve cryptography (ECC), which is one of the most powerful types of encryption in use today.
Well-Known Intervals
Listed below are many events which occur on network devices at well-known intervals. The list is provided to serve as an aid while troubleshooting recurring network disruptions.
FCC approves net neutrality rules, reclassifies broadband as a utility
Today is a good day. By a 3-2 vote, the FCC has voted to adopt net neutrality rules to protect the open Internet.
Cisco Live 2015 – Mike Rowe Announced as Keynote Speaker
Cisco just announced to the Cisco Champion community that the guest speaker for the keynote is going to be none other than …… Mike Rowe!!
BGP Communities
BGP Communities has to be one of my favorite features added to the BGP protocol.
Cisco Live 2015 – Customer Appreciation Event Featuring Aerosmith!!
Yes, you heard me right. Aerosmith! One of the most looked forward to social events for Cisco Live has always been the Customer Appreciation Events (CAE).
Binary Metal Guitar
Thank you Ed Koczan for sharing the video that led me to find this video. It’s a national treasure for those of us that appreciate binary.
Cisco VIRL released into the wild
After much waiting from all of us, Cisco has released, on “cyber Monday” no less, VIRL.
The Unofficial JNCIE-ENT Prep Guide
Some of you may have heard that Jeff Fry has published his Unofficial JNCIE-ENT Prep Guide, but how many of you have purchased it yet?
Network Design — Keeping it simple
Since the dawn of time people have skirted best practice and banged together networks, putting the proverbial square peg in the esoteric round hole.
Cisco ISR 4000 – Now with more licensing!
This week at Interop NYC, Cisco launched it’s ISR 4000 Series. This is a new approach for them focused on delivering services to your branch offices.
HP talks SDN at Interop NYC 2014
I generally try to avoid oversharing when it comes to my thoughts about presentations, but I have to mention that after sitting down with Glue Networks and their “SDN” …
Installing VMware tools on Cisco ACS
As of ACS v5.4 Cisco has finally included VMware tools for their ADE OS.
Using Deny ACEs in your PBR ACL on your Nexus 7k
Quite a while ago I had a need for some network duct tape… Policy Based Routing while useful should only IMHO be used as a temporary fix.
Vendor PSA: Words and Phrases to Avoid in Presentations
Over the years IT professionals have sat through countless presentations, conference calls, and keynotes.
Cisco ASA Packet Captures for Fun and Profit
As many of you know my background isn’t in enterprise, but I currently fill that role in my $job.
Fixing iMessage on Hackintosh
Mid December 2012 Apple shut down the Messages Beta for Lion, soon after many hackintosh users started noticing issues with signing into iMessage.
Double NAT – Cisco ASA 8.4+
Recently I was faced with an issue outside my normal expertise… those of you that know me realize I am anything but a security engineer.
Vim Primer for Network Engineers
Vi is arguably the best text editing software in the world. There, I said it… deal with it!
Cisco Nexus 2000: A Love/Hate Relationship
My feelings towards the Nexus 2000 Fabric Extender (FEX) are hardly a secret.
CCIE Potential
INE published a great info-graphic on the earning potential of Cisco’s certifications and I felt the need to share it here.
QinQ: IEEE 802.1Q Tunneling
In situations where service providers want to offer transparent LAN services that preserve a customers VLAN tags across your Layer-2 network, this amendment to the IEEE 802.
Cisco IPS Fun
Since I’ve recently had some fun working with the Cisco 5585-X and the IPS blades, I wanted to document some of the information I learned while getting them online.
Another Wicked Vim Tip
As a follow up to my blog post covering Vim on the PacketPushers blog, I wanted to share with you another time saving tip for getting our jobs done not only quickly, but helping to …
MDS Fibre Channel Switching Basics for Network Engineers
Recently I’ve been lucky enough to be challenged with learning a bit about Fibre Channel Switching, but I’m even luckier in that I’m getting to know it on a set of MDS switches …
Brocade and VCS… quite impressive
Our second visit on day 2 of Network Field day was Brocade, who incidentally supplied us with a great lunch!
Juniper QFabric, Junosphere, Automation, and More
The second day of Network Field Day 2 started early at the Juniper EBC, luckily Abner Germanow was prepared with breakfast for the weary and slightly hung over delegates.
Gigamon and the Great Pumpkin
I could’ve just as easily called this article Gigamon… fixing problems you didn’t know about or Why Gigamon scares the crap out of me — but I wont, because they already did!
NEC and ProgrammableFlow Switching
NEC is currently the only Vendor that is shipping an OpenFlow enabled product today.
Network Field Day 2 — Comic Edition
During the coarse of NFD2 I found an iPhone app called Halftone, and later, one named ComicStrip that allow you to add some fun effects and speech bubbles to your photos… So, I …
Cisco Systems Awesomesauce aka Full Tilt Boogie
First of all, I want to say thank you to everyone from Cisco Systems for inviting us into the CCIC (Cisco Cloud Innovation Center), this was an amazing room to hold our …
The OpenFlow Symposium
Well, here is the update that I promised you. I’ve spent the last few days with some of the top minds in Networking industry.
Tech Field Day: OpenFlow Symposium
What is OpenFlow? OpenFlow is a proposed standard for exchanging flow data between controllers and networking devices.
BPDU the next incrementation
As I feel this may be a regular section of the blog due to my lack of availability. Please suggest a better name for this “series”.
SNMP can save your life
Ever get locked out of a router or switch that is many hours or even days away? Recently, I had the pleasure, again.
BPDU – Blog Post Data Unit?
My most recently collection of interesting bits of data found out on the blogsphere/internets.
Best Practices and Securing Cisco IOS
Everyone has different views on hardening IOS, and while I do not claim to be an expert, these are the practices that I commonly use when bringing up a new device.
Network Duct Tape Gone Wrong
As many of you may know, I’m in the middle of a huge network redesign, last week our new firewalls finally arrived and it became time for us to start migrating services onto the …
F5’s iRules — My first look
I’ve never had the opportunity to really do much with F5 load balancers in the past, but recently one our system engineers needed some load balancing setup, and wanted to know if …
Nexus 7000 vPC Features
Next generation data centers across the world are taking advantage of Cisco’s Virtual PortChannel.
NX-OS 5.2(1) for the Nexus 7000
Rather quietly, at least I never heard anything, on July 29th, Cisco released NX-OS Version 5.2(1) for the Nexus 7000 platform.
Cisco Increases CCIE Lab Cost
This morning several CCIE candidates received an email stating that on August 1, 2011, Cisco will be raising the cost for the CCIE lab from $1,400 to $1,500.
My Toolbag
Following the current popular topic of “Whats in your toolbag?” ala Stretch and Fryguy. I’ve decided (after some persuading) to detail the contents of my own bag.
IP SLA Basics
IP SLA is a function of Cisco’s IOS enabling you to analyze a Service Level Agreement (SLA) for an IP application or service.
My Cisco Live 2011 Schedule
I finished up most of my registration for Cisco Live 2011 / #cl11 yesterday and figured I would put up a copy of my schedule.
Time-based ACLs
Ever since Cisco released IOS 12.0.1T we’ve had the ability to broaden the reach of the extended ACL to allow the influence of time.
IP Multicast Routing Concepts
Can you imagine a video conference taking place on a primarily T1 based WAN? Multiple copies of the same video stream being unicast from the host to each participant.
SVI Autostate
Switch Virtual Interfaces, or SVIs on Cisco IOS use a feature called autostate to determine the interface availability.
Nexus 1000v – Out of Ports on a Virtual Switch?
Yesterday, work presented an interesting issue I wanted to share with everyone.
BGP Essentials – The Art of Path Manipulation
Most enterprise networks use BGP to peer with their Internet Service Providers if they want to be multi-homed.
Introduction to the Nexus 1000V
The Nexus 1000V is a software-based Cisco NX-OS switch that integrates into VMware vSphere 4 and operates inside the VMware ESX hypervisor.
OSPF Graceful Shutdown
Striving to reach that last 9? Looking for a way to increase your uptime while still being able to do maintenance on your network?
IOS Embedded Packet Capture
Tired of setting up SPAN sessions? Need to do some packet analysis? Since IOS 12.4(20)T Cisco has made Embedded Packet Capture (EPC) available.
Nexus Virtual Port Channel (vPC)
The Nexus 7000 and 5000 series have taken port-channel functionality to the next level by enabling port-channels to exist between links that are connected to different devices.
Setting up a Cisco Access Server
Whether your networking lab has 3 devices or 30 an access server, also commonly called a terminal server, is the vital connection between you and those devices.
HSRP, VRRPd, and GLBP Compared
In the world of first hop redundancy, we have plenty of choices. In order to make the right decision for your network you should know the basics regarding all three.
BGP Tips! multipath load balancing
Previous thoughts on load balancing BGP were that it is not a load balancing protocol and in order to achieve any sort of balanced traffic you would have to perform some sort of …
Working with the Embedded Event Manager (EEM)
Cisco IOS has plenty of gems contained within, but few are as fun, and as endlessly useful as the Embedded Event Manager, or EEM.
More IOS Tips
Learning the particulars of Cisco IOS is one of the most valuable things a network engineer can do.
Using the Cisco IOS Archive Command
The Cisco IOS archive command is not only very useful in keeping configuration archives, but it can also be used to log commands entered into the router, along with their user …
Introduction to Private VLANs
The concepts behind Private VLANs are in fact rather simple, but it is quite easy to get discombobulated in the details.
Bidirectional Forwarding Detection
Bidirectional Forwarding Detection (BFD) is a UDP-based protocol that provides fast (very fast!) routing protocol independent detection of layer-3 next hop failures.
Measuring Cable Lengths on a Catalyst Switch
A while back, I was playing on a 3750 switch in a customers lab and came across something I’ve never seen before.
Using Discontiguous Wildcard Masks in ACLs
Unlike subnet masks, wildcard masks allow you to use discontiguous bits which enable you to match on a range of values.
Using Regular Expressions on Cisco IOS
As a followup to my previous post on Regular Expression Basics, I wanted to give a few examples on using them on Cisco IOS.
More BGP tricks
At times, the ‘rules of BGP’ don’t fit the needs of our productions networks. When we get into today’s production networks how often do book configurations apply?
iPhone – Rock App Causing Devistation
Recently, an update to all jailbroken phones could of caused major damage to anyone who uses Rock… There were several community updates in the last few days due to the iPad and new …
Cisco VOIP Basics – Call Broadcast for Cisco CME
This is the fourth and final part of my Cisco voip basics series.
Poor man's VPN connection
Have you ever needed to access a site that had an IP restriction, or one inside your remote network?
Netcat – secret weapon
Netcat or nc, is a forgotten tool in too many arsenals these days. It lays dormant waiting at the command line to make connections across the globe for you.
Connecting Dynamips to your local network (OSX)
Ever wanted direct network access to your Dynamips lab? Have you ever needed to lab something that used the SDM, but you run Dynamips under OSX?
Policy Based Routing
Policy based routing is the process of altering a packets path based on criteria other than the destination address, commonly referred to as ‘policy routing’.
The History of PING
Anyone that has touched a computer these days has probably heard of ping. But very few know of its true origins these days.
Using /31 subnets for point-to-point interfaces
Recently a “colleague”, I use that term very loosely here, was reviewing my recommendations for changes on his network.
The Holy Hackintosh Build
This is a follow up to my previous Hackintosh post chronicling the build and setup of my ‘Hack Pro’.
The Road to Hack…intosh
Over the past couple months, the lack of desktop here at home has driven me up the wall.
IOS ACL Resequencing
This is one of those tricks you wish you learned about 10 years ago, but never did. You know how easy it is to mess up a nice looking access list.
Cisco MPLS VRF Configuration and Demo
A while back I asked everyone to vote on what topic they wanted to see next, and by no surprise almost every voted for MPLS VRFs.
JunOS Olive Demonstration
As a follow up to my JunOS Olive tutorial, I made a demonstration video that shows Multicast functioning via OSPF to another Olive and an ImageStream VM.
Running JunOS under VMWare (updated – again!)
Interested in trying out JunOS? Can’t afford to build a real Juniper lab? Sounds like you need some Olives.
Mail Server Relay Testing
As you may know, I am not big in the server world, even less into mail servers. They make me sick.
Route Selection
One of the most common questions I get concerns path selection within the router.
Cisco VOIP Basics – Cisco Dial Plans
This is the third part of my Cisco voip basics series. ( Parts 1, 2 & 4 ) Our goal is to help you configure a Cisco voice gateway that you could use in your home office.
Snow Leopard – The What It Broke Edition (updated)
Snow Leopard was released on August 28th, and at 1:37pm I received my copy and proceeded to install it like a well trained puppy.
Setting up Apple Filing Protocol and Bonjour under Debian
Got a Mac ? Got a Linux box that you use as a file server on your home network? Sick of problems with samba?
Cisco VOIP Basics – Installing Cisco Call Manager Express
This is the second part of my Cisco voip basics series. ( Parts 1, 3 & 4 ) Our goal in this series is to setup a working voice gateway that you could use in your home office.
Testing TCP Connectivity on Cisco Devices
Ever thought you might be having some Layer 4 connectivity issues?
Usefull OS X Eject Key Shortcuts
Recently, I was using one of my custom short cuts and fat fingered the F12 key on my laptop… What resulted was my screen shutting off.
Juniper Fast Track Program
This summer I learned about a fantastic offer from Juniper to ‘fast track’ you into a certification.
BGP Security Tips (updated)
For some, BGP is a rather large obtrusive beast of a protocol that scares them half to death.
Configuring a Cisco Router as a Frame Relay Switch
One of the most effective lab setups uses frame relay as its primary transport method.
Google Voice Widget for OS X ‘s dashboard
Seriously… Why haven’t we seen this yet? This is the perfect application for the dashboard.
An Essential Alias for Forgetful Engineers Like Myself (updated)
How many times a day do you issue a show command from configuration mode ? If you’re anything like me, its enough to get annoying.
Setting up VOIP lab
This week I’ve started setting up a VOIP lab to explore the technology and when I’m done, I plan to integrate it into my home network.
OS X Leopard Hacks
Here are a few settings you can change using the OS X defaults command to access some system parameters.
Demystifying Cisco Config Register Bits
Ever accidentally set your config register to a random value that isn’t in the Cisco documentation? No? Neither have I, but one day I encountered someone on #cisco that had.
Securing SSH against bruteforce attacks
This is one of the methods I’ve used in the past to secure a Linux host against brute force ssh attacks.
Regular Expression Basics
Before I even get started, I want to mention that not all regular expression metacharacters are supported in every application. Keep this in mind when building your matches.
Cisco IOS Tips and Tricks
So, I’m sure these have been posted almost on every networking blog under the sun, but who knows, right?
Working on my new lab setup
So, I purchased a couple extra routers, and a second layer3 switch from @usedciscoguy.
Layer 2 Ethernet transport over OpenVPN
One of the things I used to deploy frequently at my previous position was transport for other ISPs and businesses.
Using OSPF to create unlicensed full duplex connections.
Recently one of my clients asked me to help resolve an issue at an aggregation point on their network.
How does latency effect throughput?
One of the questions I get asked several times a week by my clients is as such.
Cisco IOS Naming Conventions
As I started building this lab, I realized that I had to find a refresher course on the IOS naming conventions.
Web Searches via Quicksilver
Everyone does a fair amount of googling these days, but any network engineer can tell you that a quick ARIN whois search can be invalueable. I know I end up there quite often.
Fixing Vista Partition Error Messages when using Bootcamp
So, I had to reinstall Vista on my mac today — hadn’t touched it since I moved onto the Late 08 model… and once again, I started getting the common partition errors while Vista …
Cmd + Tab Replacement for Mac
PullTab is no longer maintained or supported. I’ve removed broken links within this article….
SSH Wrapper Script
Ok — this is my first script that I’m posting here. Its a VERY simple ssh wrapper script that you can place in your path, preferably in ~/bin bash #!
the road to Mac
I’ve been pondering it for quite some time, but yes now I have switched to Mac. I purchased a new 2.5ghz, 4gb of Ram, 15″ Macbook Pro.