Re: FreeBSD dhcp failing with UDP checksum errors

I recently reinstalled Fedora (host) and I'm trying to import a previously working FreeBSD 13 guest. It boots fine, but fails to get an address from DHCP. In the FreeBSD boot output it prints: Starting dhclient. DHCPDISCOVER on vtnet0 to 255.255.255.255 port 67 interval 7 DHCPDISCOVER on vtnet0 to 255.255.255.255 port 67 interval 9 DHCPDISCOVER on vtnet0 to 255.255.255.255 port 67 interval 9 DHCPDISCOVER on vtnet0 to 255.255.255.255 port 67 interval 10 DHCPDISCOVER on vtnet0 to 255.255.255.255 port 67 interval 17 5 bad udp checksums in 5 packets Indeed, tcpdumping the network on the host side shows that checksums are wrong (note "bad udp cksum" in the reply message): 0.0.0.0.bootpc > 255.255.255.255.bootps: [udp sum ok] BOOTP/DHCP, Request from 52:54:00:d4:07:ab (oui Unknown), length 300, xid 0xf9ee0d34, secs 53, Flags [none] (0x0000) Client-Ethernet-Address 52:54:00:d4:07:ab (oui Unknown) Vendor-rfc1048 Extensions Magic Cookie 0x63825363 DHCP-Message (53), length 1: Discover Requested-IP (50), length 4: freebsd.home.annexia.org Client-ID (61), length 7: ether 52:54:00:d4:07:ab Hostname (12), length 7: "freebsd" Parameter-Request (55), length 10: Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121) Default-Gateway (3), Domain-Name (15), Domain-Name-Server (6), Hostname (12) Unknown (119), MTU (26) END (255), length 0 PAD (0), length 0, occurs 20 13:07:37.304083 IP (tos 0xc0, ttl 64, id 20207, offset 0, flags [none], proto UDP (17), length 328) cash.bootps > 192.168.122.203.bootpc: [bad udp cksum 0x7763 -> 0x88a0!] BOOTP/DHCP, Reply, length 300, xid 0xf9ee0d34, secs 53, Flags [none] (0x0000) Your-IP 192.168.122.203 Server-IP cash Client-Ethernet-Address 52:54:00:d4:07:ab (oui Unknown) Vendor-rfc1048 Extensions Magic Cookie 0x63825363 DHCP-Message (53), length 1: Offer Server-ID (54), length 4: cash Lease-Time (51), length 4: 3600 RN (58), length 4: 1800 RB (59), length 4: 3150 Subnet-Mask (1), length 4: 255.255.255.0 BR (28), length 4: 192.168.122.255 Default-Gateway (3), length 4: cash Domain-Name-Server (6), length 4: cash END (255), length 0 PAD (0), length 0, occurs 8 I guess this is something to do with checksum offloading. I can only find ancient bugs related to this. How to fix? The host is: libvirt-daemon-10.6.0-1.fc41.x86_64 dnsmasq-2.90-3.fc41.x86_64 Linux cash 6.11.0-0.rc5.20240830git20371ba12063.47.fc42.x86_64 #1 SMP PREEMPT_DYNAMIC Fri Aug 30 15:36:28 UTC 2024 x86_64 GNU/Linux