Here we add a bunch of shorthands for the topology we're setting up,
but not for all interfaces/IPs. E.g.,

[...]

The IPs are hardcoded here (and in the rest of the code below). AFAICT the
logic is that the defines are to make it more obvious as to what the test
is about. Is there a logic of this kind behind the naming convention?

Yes, the rule is inherited from the file: a value gets a define when
setup_netns() and the assertion table both use it, so the two sites
cannot drift and a table arm names what it targets (.daddr =
IPV4_VLAN_GW reads as intent). The new defines follow that.

The hardcoded addresses are in the netns and live-frames subtests,
which build their own single-function topologies the table never
references, so there is no second site to keep in sync. The bare
"veth1"/"veth2" strings predate this series; I left them alone rather
than churn lines the series does not otherwise touch.

The netns subtest does repeat its 10.66.0.x addresses a few times,
though, so I will give those a local define in v7 to keep the new code
consistent with itself.

Thanks for the reviews!

Avi