Most SRv6 write-ups stop at “look, a VPN pings across an IPv6 core.” That is the easy part. The interesting question is the one traffic engineering asks: can I make a flow take a path the IGP would never choose, and can I prove it?
This is the first post in a hands-on SRv6 TE series. Everything here was run on a real ten-node Cisco lab, and I am showing you the configuration, the output, and the errors I hit along the way, because the errors are where the actual learning is. By the end you will have watched a path bend off the shortest route, from a single micro-SID to a two micro-SID detour, computed by a PCE and constrained by a link colour.
The platform is Cisco XRd 25.2.1 in Containerlab. XRd is a control-plane image, so the control-plane behaviour is the real result and I will be honest about where the software data plane does not follow. Nothing in this post is invented. If a command failed, I say so and I show why.