Dave Taht wrote: > hmm... bad udp checksum??? With some capture mechanisms, tcpdump gets bogus values because the hardware did the checksums. I wouldn't imagine that we have hardware checksum offload on openwrt devices, but could be. Or it's a real issue. > :/tmp# 09:12:17.404257 IP6 (flowlabel 0xdfff4, hlim 1, next-header UDP > (17) payload length: 159) fe80::20d:b9ff:fe43:a06c.546 > ff02::1:2.547: > [bad udp cksum 0x58f4 -> 0xc4a1!] On Mon, Oct 1, 2018 at 9:12 AM Dave > Taht wrote: Did you capture with -i device, or -i any? -- ] Never tell me the odds! | ipv6 mesh networks [ ] Michael Richardson, Sandelman Software Works | network architect [ ] mcr@sandelman.ca http://www.sandelman.ca/ | ruby on rails [