[Cerowrt-devel] ipv6 on comcast with 18.06.1

Michael Richardson mcr at sandelman.ca
Mon Oct 1 13:13:31 EDT 2018

Dave Taht <dave.taht at gmail.com> 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 <dave.taht at gmail.com> 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 at sandelman.ca  http://www.sandelman.ca/        |   ruby on rails    [

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