Just wanted to toss this out there in case anyone else experiences it. This is an intermittent issue that so far has been really hard to nail down because there are not really any logs or errors being generated that are helpful.
Once in a while after cold boot from power on network performance is just awful, on the LAN ports. I am running Frank’s 2.4.16 kernel on Slackware arm current for that is worth.
If you run tcpdump on a system communicating with the BananaPi-R2 you see tons and tons TCP re-transmission. I have verified all the other network hardware - by taking it out of the picture and cabling directly to the port on the Pi. Same behavior as with a switch between it and the rest of the network. Its like packets are just disappearing…
There are no errors reported by ifconfig on any interfaces, nor under runs. There is nothing in syslog to indicate anything is wrong. Nothing in dmesg, that differs from a working boot. All daemons start normally etc. The only thing logged is NFS errors if an NFS share is mounted you can see log events like “Sent X only acknowledged Y giving up.”
The problem can be detected immediately just run something like dmesg via SSH and if it takes time to scroll the text the issue is occurring, normally the buffer can be written out instantly. No performance issues can be observed on the physical console and CPU utilization is normal.
This has never occurred after a “reboot” only on cold start. A simple reboot has corrected the problem the times I have tried that without doing anything else. This has happened four times now in I think 25 power cycles. I only started making notes after the second time. I have left the device running for 9 days following a successful boot and there are no issues. So if it starts up okay its stable. Given the later, this isnt a huge issue for me but I wanted to put this out that in case anyone else sees it.