Duet2 Eth - Malformed Packets

MintyTrebor

Having a problem with my Duet 2 Eth spitting out malformed packets when its booted. Once booted, the board appears to operate normally with no further issues. Wouldn't be a problem but the malformed packets are causing the Unifi management software I use to have a cardiac arrest and require a reboot. Issue has persisted across 3.4 & now 3.5.
I have only now got around to running wire-shark to capture the network packets from the board.

I have done the obvious, and changed patch cables, switch ports, switch etc.. Any ideas?
m122.txt

dc42

@MintyTrebor please save the capture and provide the capture file so that we can see the detail of those packets.

MintyTrebor

@dc42 Thanks.
duet2eth_filtered.pcapng

MintyTrebor

@MintyTrebor By way of an update.
Jay sent me a new Ethernet module, which did not resolve the issue.
I also tried switching to a 24v Power Supply as I normally run the board on 5v usb for development, and that made no difference either.

dc42

@MintyTrebor thanks. I suspect a bug in the MDNS code for the W5500 WiFi module. Unfortunately I won't be able to look into this for a while because I have a lot of other work in the queue.

Do you have a M550 command in config.g, if so what machine name do you set?

MintyTrebor

@dc42 Yes:
M550 P"TTSPro"

(which is also the same name assigned in the dhcp server)

Not an issue, as long as I know my board is not going bad, I'm good. It only actually causes an issue because the Unifi software react so badly to the malformed packets (which is it's own issue).

dc42

@MintyTrebor thanks, that name looks harmless enough.

dc42

@MintyTrebor I've used Wireshark to look at a Duet 2 Ethernet and a Duet Maestro (which uses the same wifi module and code) while starting up, and I don't see the problem. All I see is this:

So I suspect that something else in your network is sending something to the Duet, and the Duet is responding with malformed packets.

Can you send me another pcap file but this time without filtering by IP address? To preserve confidentially you may want to send it to me by email instead of via this forum. What I need to see is whether there are any packets between the first and second ones in your capture.

I am assuming you filtered by IP address using the form "ip.addr==10.66.1.55". If instead you filtered on source.ip then it may be sufficient to send me a capture filtered by just ip. Or a capture filtered by just "mdns||igmp" may suffice.

MintyTrebor

@dc42 said in Duet2 Eth - Malformed Packets:

So I suspect that something else in your network is sending something to the Duet, and the Duet is responding with malformed packets.

Wouldn't surprise me in the least, my network is not "typical"

I'll send the data shortly.

Thanks!

MintyTrebor

@dc42 I setup a completely new network, consisting of a r-pi running as a dhcp server plus wireshark, and an unmanaged switch. This approach eliminates any external factors from my network.

Unfortunately the results are the same, the Duet2 Eth is still sending malformed packets according to the wireshark capture.

I have attached the capture file as this is essentially a sand-boxed network, with no privacy risk.

duet2eth.pcapng

dc42

@MintyTrebor thanks. Do you get the same if you use a minimal config.g file, just enough to enable the network?

MintyTrebor

@dc42 I have just tried it with a brand new SD card, and minimal config (just the network commands required for dhcp and http server), and there is no change to the malformed packet generation.

dc42

@MintyTrebor thanks. It's strange that I don't see any malformed packets on either of my machines, and the ones you see don't appear to be triggered by a packet received by the Duet.