Switching

Switching

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.

2013.08.19 · 1 min
Switching

Cisco Nexus 2000: A Love/Hate Relationship

My feelings towards the Nexus 2000 Fabric Extender (FEX) are hardly a secret.

2012.06.21 · 4 min
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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.

2012.04.19 · 3 min
Switching

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 …

2011.09.01 · 4 min
Switching

Nexus 7000 vPC Features

Next generation data centers across the world are taking advantage of Cisco’s Virtual PortChannel.

2011.08.19 · 4 min
Switching

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.

2011.08.01 · 2 min
Switching

SVI Autostate

Switch Virtual Interfaces, or SVIs on Cisco IOS use a feature called autostate to determine the interface availability.

2011.03.07 · 2 min
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Nexus 1000v – Out of Ports on a Virtual Switch?

Yesterday, work presented an interesting issue I wanted to share with everyone.

2011.03.01 · 2 min
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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.

2011.02.24 · 3 min
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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.

2011.02.01 · 4 min
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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.

2010.06.01 · 4 min
Switching

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.

2010.05.22 · 1 min
Switching

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.

2010.05.19 · 5 min