On 2025-05-08, Janne Johansson <icepic...@gmail.com> wrote: >> Now a lot of my experience here comes from Linux many moons ago. >> But I found a lot of hardware that wouldn't play nicely unless >> offloading was disabled, with the most aggravating bugs. There's >> also minor nuisances, like checksums not matching in tcpdump under >> some circumstances. And some NICs would seem to "go bad" at some > > Well, if you tcpdump packets outwards going which are going to get > their checksums done by the hw, then tcpdump will correctly state that > the checksum is bad, because it has not been done yet by the time it > picks it up.
One consequence of this (specifically wrt checksum offloading, which has been done for a *long* time on some NICs): if there's corruption on the bus, it won't then be picked up and packets dropped. I discovered this the hard way, sat in a freezing datacentre at 3am. -- Please keep replies on the mailing list.
