networking

Cisco Viptela drops the ball

In 2012, we saw the launch of Viptela, a pioneer in SDWAN network solutions. While they weren’t the first in SDWAN, I believe that badge goes to Talari; Viptela was the …

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. Enter Graphiant, a …

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 …

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. Millions of packets flowing through your network every minute of every …

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. My sources within Cisco won’t give up the goods, but many …

Networking Field Day 13 – Sneak Preview

This is going to be a busy week for the Tech Field Day family. They have delegates en-route to Tech Field Day 12 this morning, and Wednesday the crew for Network Field day 13 …

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. But in reality, there are …

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. With almost 5,000 flights grounded, and NYSE halting trading the cost …

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. …

BGP Communities

BGP Communities has to be one of my favorite features added to the BGP protocol. As you should know by now, BGP passes several attributes between peers that help influence the

Cisco VIRL released into the wild

After much waiting from all of us, Cisco has released, on “cyber Monday” no less, VIRL. As you may remember, VIRL was the talk of CLUS 2013, and many of us have been eagerly …

The Unofficial JNCIE-ENT Prep Guide

Some of you may have heard that Jeff Fry has published his Read More

AS-Path Filtering

Before we get into the how, let’s talk about the why. According to the CIDR Report, the global IPv4 routing table sits at about 525,000 routes, it has doubled in size since mid …

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. For example, new vendor XYZ’s …

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. Cisco has dubbed this new …

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” …

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. It covers a range of topics from average salaries on all …

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 802.1q …

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! We spent a little time going through the expected marketing …

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. He gave …

Gigamon and the Great Pumpkin

I could’ve just as easily called this article

NEC and ProgrammableFlow Switching

NEC is currently the only Vendor that is shipping an OpenFlow enabled product today. So naturally, their presentation led off with a message about what they’re bringing to the …

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. One of the most exciting technologies being presented …

Tech Field Day: OpenFlow Symposium

What is OpenFlow?

OpenFlow is a proposed standard for exchanging flow data between controllers and networking devices. OpenFlow has the potential to move our networking control …

Networking Field Day 2

Have you heard the news? You’re ~~least~~ favorite blogger is making the trip to San Jose California for Tech Field Day: Network Field Day 2 — I really want to add a dramatic movie …

BPDU – Blog Post Data Unit?

My most recently collection of interesting bits of data found out on the blogsphere/internets. Due to my lack of time, I’ve decided to recycle what I find out on the ‘net and share …

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 …

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. Multiple …

Public Service Announcement for Engineers

We all know how stressful our jobs can be. And we certainly know about our own hot button issues that press on the nerves in our brain, resulting in great pain and agony which in …

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. Many factors come into play when determining how traffic should flow, …

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. With the 1000V your virtual servers have …

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. The following …

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 these within routing protocols is typically frowned …

Poor man's VPN connection

Have you ever needed to access a site that had an IP restriction, or one inside your remote network? Recently I need to access a customers remote monitoring site, but its …

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. Knowing how to use it, …

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. The following is based off the original developer, Mike …

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. Since they’re rather tight on public IP space, and require …

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. When I started working on this, I decided to take …

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. But, today I found a nifty little tool you can use to test your mail server …

Juniper Fast Track Program

This summer I learned about a fantastic offer from Juniper to ‘fast track’ you into a certification. They’re offering training material, and if you can pass their pre-assessment …

BGP Security Tips (updated)

For some, BGP is a rather large obtrusive beast of a protocol that scares them half to death. This is not without good reason as BGP is not only the most important protocol running …

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. While its not a perfect method, it does a good job of preventing 100s of …

Working on my new lab setup

So, I purchased a couple extra routers, and a second layer3 switch from @usedciscoguy. He gave me a really good deal and I plan on purchasing a 6500 series switch from him as soon …

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. Since MPLS support is in its infancy on the Imagestream platform, …

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. They had several connections that converged onto a single unlicensed link on …

How does latency effect throughput?

One of the questions I get asked several times a week by my clients is as such. While most people never associate latency with the amount of data they can send across a single TCP …