#2510: Adding IPv6 cases to transport tests

[CtrlAltGiri]

Fixing #2510

[marten-seemann]

This will double the run time of this test suite, which is already taking 10s, and we'll be adding more tests in the future. Should this instead be a single IPv6 test?

[MarcoPolo]

Great to see no failures!

I think another 10s is an okay tradeoff because:

1. We don't really test IPv6 anywhere else.
2. We really want to test all the things you can do with a transport, this includes doing all those things with IPv6 as well.

Should this instead be a single IPv6 test?

I think if IPv6 had been interoperable with IPv4, this would be something I would agree with. Sadly, we are living in a two stack world, so I think it makes sense to run all these tests with IPv6 as well.

[marten-seemann]

2. We really want to test all the things you can do with a transport, this includes doing all those things with IPv6 as well.

Lots of the tests test functionality that's going on on top of an established connection, for example the stream deadline test, gating test, etc. There's not a lot of value in running those on IPv6, is there?