For the details on what Overlay Transport Virtualization (OTV) is and how it works on a high-level, see my previous blog … [Read more...]
Cisco Nexus – Port “Inactive” Status
18 April 2013 by 4 Comments
Quick notes on the "inactive" port status seen on the Cisco Nexus platform, which was perplexing the first time I ran into … [Read more...]
My First Junos Switch: Detailed Review After Three Days Under the Covers
25 February 2013 by 7 Comments
Background This post is the story of my first practical look at Junos on Juniper EX-series switches. One day last … [Read more...]
Benefits & Limitations of SPAN Ports
14 February 2013 by 9 Comments
A mirror or SPAN (switch port analyzer) port can be a very useful resource if used in the correct way. SPAN ports are … [Read more...]
OpenFlow Switching Performance: Not All TCAM Is Created Equal
1 February 2013 by 7 Comments
The fundamental promise of OpenFlow - that any switches and any controllers can be used to build a network - was perhaps … [Read more...]
Understanding Crossbar Fabrics & The iSLIP Algorithm
27 January 2013 by 6 Comments
Reading through a Cisco paper on the Nexus 5548P switch architecture, I came across the term iSLIP. "The [Unified Crossbar … [Read more...]
Extending Layer 2 Across Layer 3 With L2TPv3 Pseudo-Wires
22 January 2013 by 4 Comments
Imagine one day your boss comes to you wanting to provide Internet access for a tenant in a distant building location that … [Read more...]
Configuring Mixed-Mode Virtual-Chassis With Juniper EX-Series Switches
13 November 2012 by 1 Comment
Recently I was building a Virtual-chassis with Juniper EX-series Switches. I'm now sharing my experience. Virtual-chassis … [Read more...]
VTP V2 Transparent Mode: Mismatched Domain Names Cause Advertisements to Be Dropped
7 October 2012 by 10 Comments
Cisco's documentation on VTP version 2 transparent mode states that it will pass VTP messages without inspecting the domain … [Read more...]
Time Warner Cable Ubee Modem: Auto-Negotiation Failure Results in Poor Internet Performance
5 October 2012 by 12 Comments
Last week, I visited a client to test their Internet speed. The company is paying for a 35Mb/s down and a 5Mb/s upload speed. … [Read more...]
Revenge of the TOE
27 September 2012 by 7 Comments
Recently a colleague and I encountered a very perplexing issue with one of our ASAs. Our team had reports of users … [Read more...]
Five Things to Know About DHCP Snooping
25 September 2012 by 7 Comments
This is a new format of blog post I'm trying out. The idea is to put key points about a technology into easily digestible … [Read more...]
No, Not That Kind of Model!
15 August 2012 by 10 Comments
We're not selling clothes, after all. Ivan and I have been tossing emails back and forth about Openflow over the last week … [Read more...]
CCNP Studies: Configuring DHCP Snooping
3 August 2012 by 5 Comments
I've been enthralled with the security features for Catalyst switches. I've had to plug away at the theory and lab work … [Read more...]
CCNP Studies: Configuring HSRP – Part Two
12 July 2012 by 5 Comments
Welcome back! Today, we’ll continue with HSRP, working with a slightly more complex topology. If you haven’t read part … [Read more...]
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