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Poor Ethernet Connectivity, Cannot Establish FTP Connection, Davinci DM6446 , MontaVista

I have a Davinci DM6446 board running MontaVista. I am not able to establish a reliable FTP connection. My desktop has vsftpd installed and apparently configured correctly (because I can access it from other computers on my network). When I login to the board through the serial port, I can start an FTP session. Sometimes it asks for username, sometimes it gets to password, sometimes it makes it all the way to being logged in, but I can't "get" files or "ls" in the directory. It will say 150 Here comes the directory listing, but hang indefinitely. Or if I start a transfer it will sometimes start the transfer and list the filesize but hang.

To debug the issue I have attempted to ping the box from my desktop and vice versa. When doing this ~50-80% of the packets are being lost. I'm assuming that this is what's causing the problems. I've tried doing a ping localhost on the desktop and on the board to rule out that one of them is too busy with their own requests. When pinging themselves no packets are dropped. To rule out the router, I've connected to the FTP server on the desktop from a laptop and was able to transfer files, I've also pinged the laptop from the desktop without packet loss.

I have an ethernet cable going from the board to the router. I have another cable from the router  that is plugged into my desktop. When they connect, my desktop gets IP assigned automatically by DHCP but the board doesn't. On the board I do a "ifconfig eth0 192.168.2.3" to set it to an ip address on my desktops (192.168.2.2) network. If needed I set the netmask as well. After this setup I am able to ping, but have extreme packet loss.

Does anyone have any ideas of what could be wrong? Is there a way to transfer files through serialport that could bypass this? 

  • We had one Davinci DM368 IPNC with extreme packet loss and unreliability like you describe. It is a different board, but maybe your board has the same issue. In our case it turned out to be the 25 Mhz crystal or oscillator for the Ethernet chip. Maybe put a scope on that and see if there is a problem with that clock source.

  • Thanks for the suggestion. Luckily I won't have to try this for the time being. It seems to be working today (after about a week of not working). I replaced all ethernet cables and am using a different router. I tested it on two Linksys routers and both worked. The one I'm currently using is a Linksys WRT54GC router. 

    I'm not sure what the issue was. Possibly the oscillator is going bad like you mentioned. If this is the case, maybe being powered down for a couple days has helped to reset it temporarily.