I agree that this doesn’t seem to have been written by someone that actually understands the topic.
Even the network diagram at the beginning is not very good. Can you create network architectures where 10.0.0.1 and 10.0.0.2 are not layer 2 adjacent? Yes, but they’re fairly complex and would imply that a lot of other necessary information is missing from the diagram. And should you use such an architecture as an example to explain traceroute? Absolutely not. It’s hard to imagine someone with even a CCNA level understanding of networking coming up with this.
Glad I'm not the only one who was bothered by this. No subnet masks in the diagram, and I'm supposed to assume that 10.0.0.1 and 10.0.0.2 are not in the same broadcast domain. So my default gateway is what, 10.0.0.0, and that router has a route to 10.0.0.2/? with a next-hop of 10.1.0.5?
Wackiest network I've seen in a while, and I've seen some real winners.
/31 linknets are common in the ISP world, it might even be /32 loopback of those devices, who knows.
I do agree that its bad but not for the same reason. On the diagram it looks like router IPs are their loopback IPs rather than the link IP, as we know a traceroute response comes from the interface the packet came in and that IP is used in the response. Seems like the creator tried to simplify the diagram and excluded linknets but made it more confusing instead.
Even the network diagram at the beginning is not very good. Can you create network architectures where 10.0.0.1 and 10.0.0.2 are not layer 2 adjacent? Yes, but they’re fairly complex and would imply that a lot of other necessary information is missing from the diagram. And should you use such an architecture as an example to explain traceroute? Absolutely not. It’s hard to imagine someone with even a CCNA level understanding of networking coming up with this.