Author Archives: RedNectar Chris Welsh

About RedNectar Chris Welsh

Professional IT Instructor. All things TCP/IP, Cisco or VoIP

CSMA/CD and full duplex for wireless? It could be coming

Posted on 2018/03/23

The problem with existing wireless communications is that once a device starts transmitting, it doesn’t know if another device has transmitted at the same time until it has finished transmitting. This may be the solution to evercome that Continue reading →

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Posted in blog, opinion, wifi, wireless network | Tagged ,

Why have WordPress made it soooo hard to follow someone?

Posted on 2018/03/23

 I won’t start a tirade of things you STILL can’t do on WP, but I am going to have a whinge about one feature you have obscured. Continue reading →

Posted in opinion, rant, wordpress | Tagged | 2 Comments

RedNectar’s HX Pre-Install Checklist

Posted on 2018/03/18

…has been updated and is found here: https://rednectar.net/2018/10/06/rednectars-hyperflex-pre-install-checklist-updated/

Posted in Cisco, Data Center, Data Centre, Hyperflex, UCS | Tagged , , ,

ISIS, COOP, BGP and MP-BGP in Cisco ACI

Posted on 2018/03/01

Let me start with a picture.  Imagine a simple 2leaf/2spine topology with HostA attached to to Leaf1 and with HostB attached to to Leaf2. Enter IS-IS. The leaves and spines will exchange IS-IS routing updates with each other so that Leaf1 sees that it has two equally good paths to reach Leaf2, and Leaf2 sees that it has two equally good paths to reach Leaf1. Now think about the hosts. This is where COOP comes in. BGP is not needed until an external router is connected. Continue reading →

Posted in ACI, ACI configuration, APIC, Cisco, Data Center, Data Centre, EPG, L3 Out, L3out | Tagged , ,

Guest Post! WTF Are all those Checkboxes? (ACI L3 Outs) – Part 2 of ???

Posted on 2017/07/22

Originally posted on Come Route With Me!:
My friend and colleague Mr. Jason Banker recently ran into some good times with the mysteries of the ACI L3 Out Checkbox Madness! He Slack’d me and told me he’d found some clowns…

Posted in GNS3 WorkBench

Non overlapping VTEP IP addresses in Cisco ACI

Posted on 2017/06/13

Cisco recommends that “The TEP IP address pool should not overlap with existing IP address pools that may be in use by the servers (in particular, by virtualized servers).”
Let me tell you a reason much closer to reality why you might want to avoid overlapping your Cisco ACI TEP addresses with your locally configured addressing scheme. Continue reading →

Posted in ACI, ACI configuration, APIC, Cisco, Data Center, Data Centre | Tagged , , , ,

Cisco ACI Naming Standards

Posted on 2017/05/19

Have you ever wondered what a L3 Out object is, when there no facility to create an object called L3 Out? I managed to solve this and many other ambiguities by developing and adopting a consistent naming standard. Continue reading →

Posted in Access Policies, ACI, ACI configuration, Cisco, Data Center, Data Centre, Nexus, Nexus 9000, SDN, Software Defined Networking | Tagged , , , , | 1 Comment