Ansible has a very neat feature called “fact gathering”, which collects useful information from hosts prior to executing any of the tasks and makes this information available for use within those tasks. Unfortunately, this also relies on Python being available on the remote machine which doesn’t work for Cisco IOS. In this post I’ll show how to write a simple module which will collect IP address information from remote devices and store it in global variable for future use. I’ll also show how to write a module which will convert our human-readable TDD scenarios into YAML structures. As always, full code repository is available on Github
Continue readingAn anonymous commenter wrote this comment to my initial SD-WAN post:
I can still hardly imagine the business case behind SD-WAN. Any thoughts?
This question is really easy to answer. There’s a huge business case that SD-WAN products are aiming to solve: replacing traditional MPLS/VPN networks with encrypted transport over public Internet. However…
Read more ...In this YouTube “playing in the lab” IWAN fun we are going to have 2 phones (one in Branch 1 and one in Branch 3) doing a voice/video call. We will use LiveAction to see that the video call between the 2 branches is actually going directly spoke-to-spoke despite the fact that they are on an mGRE tunnel with a DMVPN hub in the Hub Site. We will confirm what LiveAction is seeing via command line on Branch1 Router 1 and see the NHRP shortcuts that this router has to go directly to the Router 3’s direct IP address that it uses to connect to the MPLS cloud.
We will then ask what might happen if a brownout impairment were to occur on the Branch1_Router1 link with the MPLS PE. For example – 2% loss. We will look at a little of the PfRv3 configs up on the domain master controller as well as Branch1_Router1’s master policy that it received from the domain master controller. Then we will cause impairment (2% loss) to the MPLS link… during which I have a video recording of the phone call… where … pretty much… the move over from the primary Continue reading