Using Python to Calculate Cisco SD-WAN Tunnel Numbers – Part 1
When using Cisco SD-WAN on IOS-XE, it uses tunnel interfaces to configure parameters of the implementation. There is a mapping between what interface the tunnel is sourcing from and the name of the tunnel interface. For example, if the tunnel source is GigabitEthernet0, the tunnel interface is Tunnel0, if the tunnel source is GigabitEthernet0.100, the tunnel interface is Tunnel100000. When provisioning a router and not using Zero Touch Provisioning (ZTP), you build a small bootstrap configuration that configures mandatory parameters such as Site ID, System IP, Organization Name, but also a tunnel interface to be able to connect to the controllers. It is possible to create this configuration in vManage, and hence find out the tunnel interface name, but I thought it would be interesting to do this with code and not be dependent on vManage.
In this post, I will describe the code I used and what my logic was when creating different parts of the code. In this first post I will use the code that I came up with. In the second part, my friend Rodrigo who runs an excellent Python blog ,analyzed my code and came up with improvements, which I will describe in that Continue reading


Understanding a dual nature can be hard


















