[18373207] Duo Slow NFS Reads, Jumbo Frames and TCP window

I can't believe I have the only two ReadyNASs sending Jumbo Frames when they are disabled in Frontview. I have this problem on both my Duo and my NV+.
I would appreciate it if someone else here could check to see if their ReadyNAS Duo or NV+ is sending Jumbo Frames with that function unchecked in Frontview / Network / Interfaces / Ethernet (Make sure the MTU is also set to 1500). If interested, you can capture the packets with tcpdump and read the file with Wireshark. tcpdump is not native in the ReadyNAS. You will need to connect to the readyNAS with an ssh client, then:

apt-get install tcpdump

While still in the ssh terminal window, run this command to capture a network trace file. You will need to start a large data transfer from the ReadyNAS to the client first, then start tcpdump.

tcpdump -s 192 host <ip address of your client> -w /c/backup/tcpdump.cap

Let the capture run for a few seconds, then abort the capture. To stop the capture, you must press [Ctl]+[C]
The above will save only the first 192 bytes of each packet, which will capture all the headers up through application (nfs in my case), but not your payload data. It will write the trace to the backup share where you can view it with your windows client, and maybe post the results to this forum, should you choose. The host argument will limit the capture to traffic between the ReadyNAS and the clinet you are useing for your test.

Wireshark is certainly one of the best programs available to read your trace file. It is free and can be downloaded here: http://www.wireshark.org/download.html After you have Wireshark installed on your Windows PC, you can double-click the trace file and it will open to the summary screen. The sixth column is the Length of the packet. If you see any values in this column greater than 1514, the ReadyNAS is useing Jumbo Frames!