Re: vtnet rxcsum broken for forwarding RELENG_13 ?
Date: Tue, 12 Apr 2022 10:43:10 UTC
On 12 Apr 2022, at 2:07, Matt Garber wrote: > On Mon, Apr 11, 2022 at 7:15 PM mike tancsa <firstname.lastname@example.org> wrote: > >> I was setting up a VM pf firewall and noticed I was not able to nat out >> for some reason. Looking at the pcap, it seems when the vm is in >> forwarding mode, I get tcp checksum errors. If I do a >> >> ifconfig vtnet1 -rxcsum >> >> ifconfig vtnet0 -rxcsum >> >> nat then seems to work fine >> >> The setup is a simple VM with the hypervisor libvirt/KVM ubuntu 20 LTS. >> Guest is RELENG_13 from Apr 11/2022. If I change to em nics in the VM, >> all is fine out of the box. >> >> >> I opened up https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=263229 > > > > Unless someone knows otherwise, I’ve been under the impression that PF — or > potentially any of the other FreeBSD firewalls (?), but I use PF — has been > “broken” in that regard on Linux KVM-based FreeBSD guests for years. As > such I’ve always needed to use csum_disable flags on the vtnet interfaces > or suffer *extremely* poor network performance, even for servers not doing > NAT forwarding. > That PF checksum issue was fixed c110fc49da2995d10d60d908af0838ecb4be9bee, back in 2015. Kristof