June 18, 2025 12:27 PM, "Jan Stary" <h...@stare.cz> wrote: > On Jun 18 08:58:41, cont...@mtorres.fr wrote: > >> I've been seeing the same kind of issue on different hardware (both >> CPU/GPU/NIC). Inconsistent ping >> latency and reduced download speed. I don't see it much on my local network, >> way more towards hosts >> on the internet. For me the trigger is if there's a vlan interface on the >> OpenBSD side. > > Or any other thing on any of the hops inbetween, > about which you can't know anything (OS, HW, MTU, bufsizes, ...). > > What exactly is the issue? > >> Without a vlan interface: >> 64 bytes from 1.1.1.1: icmp_seq=11 ttl=57 time=3.886 ms >> 64 bytes from 1.1.1.1: icmp_seq=13 ttl=57 time=7.042 ms > > That's almost double. So what? > >> With a vlan interface: >> 64 bytes from 1.1.1.1: icmp_seq=3 ttl=57 time=4.299 ms >> 64 bytes from 1.1.1.1: icmp_seq=7 ttl=57 time=31.252 ms > > That's sevenfold. So what?
The 'what' is that it is consistent with having or not a vlan interface on the machine. Tests are not just a one-off, they were repeated tens of times, and the only thing that would make the latency inconsistent or the bandwidth to be down is where is the vlan 'terminated'. If the vlan interface is on the machine, I have inconsistent latency and severely limited bandwidth. If the vlan is handled by the switch, no issues at all. My question is what can I check/try to see why this happens? I'm going to try to reproduce locally, but for now I couldn't find a way to do it. Best, Mickael
