Network topology validation with CDP and Python

As most IT professionals I usually configure network devices in a lab environment before the actual installation at customer site. I try to limit the installation as much as possible to a simple box moving process, spending most of the change window in a previously defined validation process. In this particular case I deal with a data center core network that includes 8 Nexus 9k switches configured in 4 VPC pairs and a bunch of links between them.

Cisco Nexus 9000 training DCINX9K

This week I attended a two days training of Cisco DCINX9K. The training is focused on Cisco Nexus 9000 switches in NX-OS mode. NX9K can run two different software images, the full ACI image with all the cool SDN stuff and the traditional NS-OX image with some cool features like Python, Rest API, VX-LAN and more. Now it’s time to improve my Python skills and borrow a couple of boxes to do some labs.

MTU on Nexus switches - CDP and vCenter

Some time ago I’ve installed the new core switches for a customer: a couple of Nexus 7000, a couple of 5000 and twelve Nexus 2232TM, Virtual port channels, VLANs, Radius auth and so on.. all the usual configs a good network engineer does. Since the Nexus 5000 are connected to an iSCSI storage I’ve configured Jumbo frames. Customer called complaining that MTU isn’t correctly set and I must fix it.