On 8/27/22 3:36 PM, Mel Beckman wrote:
No. In fact, a lot of low-end Ethernet interfaces are completely implemented in
interrupt-driven driver software that runs in the host OS (such as Windows).
The only thing the hardware provides is the magnetically to transduce binary
bit streams.
Even MAC-address decode is in software, and as a result, broadcast storms can
slow these hosts to a crawl as the CPU had to check and discard every broadcast
packet as “not mine”.
When these tasks are offloaded from the CPU to the Ethernet hardware, the CPU
doesn’t need to perform these tasks, reducing CPU workload. These also
offloading resources provide parallel computing and validation of checksums,
which is otherwise computationally expensive.
I don’t know how this particular ONT bug works, but I’m guessing that it
results in checksum failures under certain conditions, leading to
retransmissions.
Yeah, sorry brain fart. I'd be surprised if that were a big issue on
home networks, but who knows.
Mike
-mel via cell
On Aug 27, 2022, at 3:08 PM, Michael Thomas <m...@mtcc.com> wrote:
On 8/27/22 12:00 PM, Sean Donelan wrote:
Hopefully, my pain will help someone else.
I've had sporadic Internet slowdowns and stuck networking since IPv6 was
enabled on my FIOS ONT a few months ago.
After too much troubleshooting, I found out some older Intel GbE ethernet cards
have a IPv6 Checksum Offload incompatibility with certain fiber ONT terminals.
As Verizon is enabling IPv6 on its FIOS network, you might find intermittent
network problems.
Intermittent are the worst kind of problems.
In some situations where a client machine is connected via some specific
Optical Network Terminals (ONTs), and data is appended after the packet
checksum, the network adapter can drop receive packets when using TCP-IPv6
Checksum Offload for receive traffic.
Intel published an alert in 2017, but I didn't have IPv6 on FIOS then.
https://www.intel.com/content/www/us/en/download/19174/disabling-tcp-ipv6-checksum-offload-capability-with-intel-1-10-gbe-controllers.html
TLDR; turn off TCP IPv6 Checksum Offload
Affects all operating systems (Windows, BSD, Linux, etc) using the affected
wired Intel ethernet controllers. Not a problem with Intel WiFi.
My reaction is "offload from what"? Isn't this all done in silicon?
Mike