cisco

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 …

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 …

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. Until this week, none of us had very good …

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. While ECC has been in use …

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!! In case you don’t know, Mike Rowe is an …

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). Cisco rarely let’s us …

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 …

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 …

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 …

Installing VMware tools on Cisco ACS

As of ACS v5.4 Cisco has finally included VMware tools for their ADE OS. Unfortunately, when you upgrade, they do not get installed automatically as the installation is triggered …

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. But as you know, temporary things soon …

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. In order to succeed I’ve had to develop many new skills including learning Cisco …

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. But in reality, you must always expand your …

Cisco Nexus 2000: A Love/Hate Relationship

My feelings towards the Nexus 2000 Fabric Extender (FEX) are hardly a secret. The myriad of design choices and platform limitations present engineers with some rather difficult …

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 …

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. Some of this …

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 …

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 …

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. For some reason, be it the consultant that was turning up our …

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 …

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. If you see …

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 …

Nexus 7000 vPC Features

Next generation data centers across the world are taking advantage of Cisco’s Virtual PortChannel. As of recent, I’ve moved our core to a pair of Nexus 7010s running vPCs to the …

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. (and the world rejoiced) This long awaited revision …

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. This is an interesting …

Cisco Live 2011

It’s been a tough week since I left Las Vegas. I must say that my Cisco Live withdrawal has been pretty bad, and with the week we’ve been having here in Indiana, I’m certainly …

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. IP SLAs use active traffic-monitoring to continuously …

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. My only wish would be that there was more times …

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.

Remote Configuration Tip

I got asked a rather interested question the other day. An engineer needed to make remote configuration changes to a router, but do the commands he needed to run, he would be …

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 …

SVI Autostate

Switch Virtual Interfaces, or SVIs on Cisco IOS use a feature called autostate to determine the interface availability. By default an SVI will show an up/down (Status / Protocol) …

Nexus 1000v – Out of Ports on a Virtual Switch?

Yesterday, work presented an interesting issue I wanted to share with everyone. While configuring a new virtual machine one of our systems engineers was presented with an issue he …

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 …

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? Wish you could shutdown your OSPF neighbors like …

ASA v8.4

Less than a year after changing the rules with ASA version 8.3, Cisco has released a new OS version 8.4. Since I won’t be covering the release notes word for word, you can find …

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

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. For this purpose …

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 …

Petition Cisco for Educational IOS Licensing

Greg Ferro of Etheralmind.com has started a petition asking Cisco to embrace those who pursue Cisco’s certifications a …

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. To define it simply, EEM is a technology that …

More IOS Tips

Learning the particulars of Cisco IOS is one of the most valuable things a network engineer can do. These skills will be the basis of everything you do on the lab and on your …

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. In their simplest form, PVLANs can dissociate ports within …

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. BFD can be …

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. It seems that some Cisco switches have a built in Time-domain …

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 …

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 …

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? I’ll tell you one …

Cisco VOIP Basics – Call Broadcast for Cisco CME

This is the fourth and final part of my Cisco voip basics series. ( Parts 1 , Read More

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’. PBR (Policy Based …

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 …

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. You get one setup on the router, …

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 …

Route Selection

One of the most common questions I get concerns path selection within the router. Everyone knows (or at least they should know) that a more specific prefix will be preferred, but …

Cisco VOIP Basics – Cisco Dial Plans

This is the third part of my Cisco voip basics series. ( Parts 1 , Read More

Cisco VOIP Basics – Installing Cisco Call Manager Express

This is the second part of my Cisco voip basics series. ( Parts 1 , Read More

Testing TCP Connectivity on Cisco Devices

Ever thought you might be having some Layer 4 connectivity issues? Pings as you should know are …

Cisco VOIP Basics

This is the first part of my Cisco voip basics series. ( Parts 2 , Read More

Configuring a Cisco Router as a Frame Relay Switch

One of the most effective lab setups uses frame relay as its primary transport method. This is a configuration that many people use and praise for its ease of setup and …

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. Luckily Cisco has given us the ability to user …

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. So far I’ve purchased the following for my …

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. So I …

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? Here are a few tips and tricks to help you move around the IOS a bit …

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 …

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. They have gone through a number of revisions through the years, but …