To get a seper­ate net­work stack per jail you need to wait for the VIMAGE work to be pro­duc­tion ready (a lot of code is already in 9‑current).

I know about send-/recvspace, and that it is auto-tuning (in lin­ux this seems to be a fixed inter­face spe­cif­ic set­ting, while in FreeB­SD it is a glob­al option but auto-adapting).

The size of dri­ver buffers is what this post­ing is about, and I have con­fir­ma­tion that it is not con­fig­urable. Mak­ing it con­fig­urable at run-time is a major task (some Intel dri­vers are already pre­pared as they share code with the Lin­ux dri­ver), I was told. Mak­ing it a boot-time tun­able could be fea­si­ble, but our “NIC guru” does not know how much free time he can invest into this. He wants to take care about this at least in new dri­vers he develops.