replace lo interface with dummy interface

[murex971]

Fixes: #422

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[Tuetuopay]

Hi!

Just to let you know, #527 contains another fix fo #422. It still keeps using loopbacks, but runs tests in dedicated namespaces. (See https://github.com/aya-rs/aya/pull/527/commits/9da1dfecd977ed86199fca5d80ac6d35dbce443f)

Using loopbacks has advantages compared to dummy interfaces: they loop back the traffic. In other words, any packet transmitted on the loopback is recieved on the same loopback. This is very useful for testing, especially XDP which only works in rx.

To get the same feature level, you’d need veth pairs. However that’s another can of worms, as IP configuration is required, and configuration that does not conflicts with the host machine. You could use vrfs or netns, but it’s gonna be complicated.

So yeah, for the current tests where we don’t test at all by sending packets it’s fine. But as soon as tests start to do it, dummy won’t cut it.

[mergify[bot]]

@murex971, this pull request is now in conflict and requires a rebase.

[mergify[bot]]

@murex971, this pull request is now in conflict and requires a rebase.