In this post I’m using DNAC version 184.108.40.206 for demonstrate what happens when you discover a switch using DNAC. Previously I’ve written similar posts: DNA Center - PnP - What It Does To Your Devices DNA Center - Provision - What It Does To Your Devices Test Case One simple test case is all we need to see what DNAC does: Manually configure a Cat9300 switch Add the switch to DNAC using a discovery job Topology The below topology is used for this post:
In this post I’m using DNAC version 220.127.116.11 to demonstrate what DNAC does to your device when configuring the network settings in DNAC. Previously I’ve written similar posts: DNA Center - PnP - What It Does To Your Devices DNA Center - Discovery - What It Does To Your Devices Test Case One simple test case is all we need to see what DNAC does: Manually configure a Catalyst 9300 switch Add the switch to DNAC manually via inventory Topology The below topology is used for this post:
DNA Center is a management platform that enables users to bring automation to their network. It also offers an assurance feature that aids in troubleshooting and ensuring the network runs as it should using 360 views with health status of network, client, and apps. The latter will not be in focus for this post. Rather a closer look at what DNAC actually does to your devices in regards to configuration will be revealed.
DNAC is very cumbersome and time consuming to install. It can easily take an entire day to do the initial installation and deployment of packages. At the time of writing, Cisco has not published their documentation of how to perform password recovery of DNAC. If you forget or lose your maglev or admin password, your only option is to call your Cisco partner and hope they have a how-to, or create a TAC case.
I’ve gone over the Cisco PnP feature before. This time I will revisit the feature with focus on other areas. Specifically these cases will be discussed: PnP with Non-Vlan1 (conditionally) Re-use DHCP-assigned IP address on another interface PnP with an EtherChannel PnP With Non-Vlan1 (Conditionally) I briefly discussed this in my original post, but I ran in to a case where I actually wanted both a startup-vlan and the default of Vlan1.
This post will look at how QoS works in an MPLS environment. The default behaviour of MPLS QoS is shown. Next, I’ll explain and demontrate the three MPLS QoS DiffServ Models - Uniform, Pipe, and Short Pipe. As usual expect both configuration examples and wireshark captures. Do not expect fancy QoS policies as this post’s goal is to reveal the concepts of the technology rather than focus on QoS in itself.
One of the main reasons to buy a DNA Center is to be able to harvest the benefits of automation. Many people associate DNAC with deploying an SD-Access network. SDA has a lot of focus these days and Cisco pushes hard to get it out there, but DNAC has many other uses cases besides SDA. SDA is actually just an application that you can install on a DNAC. It isn’t even installed by default when deploying a DNAC.
Segment Routing (SR) is also known as SPRING (Source Packet Routing in Networking). Two flavours of SR exist: SR with MPLS SRv6 (IPv6 Segment Routing Header (SRH)) I will only cover SR with MPLS in this post. If you know MPLS it will be fairly easy to learn about SR. If we quickly look at the name of the feature and break it down, it will make sense what its all about.
I’ll use the following topology: Terms Term Description CE Customer Edge PE Provider Edge U-PE User Provider Edge N-PE Network Provider Edge UNI User Network Interface VFI Virtual Forwarding Instance VFI is also called VSI (Virtual Switching Instance). Cisco uses the term VFI. Introduction VPLS is an MEF E-LAN service (MP2MP). H-VPLS (Hierarchical Virtual Private LAN Service) is a way to scale VPLS.
I’ll use the following topology: The basic idea about MPLS TE affinity is to add an attribute to a link and be able to include or exclude this link during path calculation. The concept is also known as link coloring. Affinity is configured on links using the mpls traffic-eng attribute-flags interface command. The values is expressed in a 32-bit hexadecimal number. By default a link has the number 0 (or 0x0).