Diffserv, 802.1p, and all that jazz

[Harvy66]

Just making sure I'm getting some of this correctly

I'm trying to get Diffserv and 802.1p to interact with my traffic shaping, so I have a few questions.

Under floating rules, I see 802.1p, which has two options, "Choose 802.1p priority to match on" and "Choose 802.1p priority to apply". I assume these work exactly as they sound, one is used for rule matching and the other will change the code.

Another quick question about 802.1p. 0 is default, 1 is lowest, and 2+ are increasingly higher priority over 0?

"Diffserv Code Point" option. Is this for matching? Is there a way I can set it?

And just to make sure I have this basic concept correct, 802.1p is at the Ethernet layer and Diffserv is at IP?

[Harvy66]

I just read that ECN uses the two right most bits of the ToS. It looks like the Class selector values all have their right most values set to 0, so I assume they're fine. But here's a question. If PFSense matches on exact values, and the two right most bits get changed by ECN, won't this break the whole exact matching or does PFSense match Class selector values in a way that ECN doesn't break it?