RN104 (perf) MTU / Jumbo Frames not working

Honestly I don't think the 104 can handle it, probably the bigger ones can 300 and 500 series (somebody please correct me if I'm wrong).

The RN104 configuration interface give the possibility to change the size of MTU, so I suppose that the integrated network card are compatibles to work with a modify MTU.

Otherwise, I will cry and buy another concurrent nas :cry:

Don't cry yet as I'm not a 100% sure. :)

Have you tried matching the MTU of the NAS and the PC's NIC?

example:

MTU/Jumbo set on GS108T: 9000
MTU/Jumbo set on NAS: 9000
MTU/Jumbo set on PC: 9000

The GS108T should be set to 9216 (the max). It includes ethernet framing overhead, but the PC and NAS software do not (so it needs to be set higher than 9000 in your example). It's safe (and easiest) to set it to the max value.

For the other devices you want to find the smallest MTU that they all support, and set the NAS and the PC to that value.

Yes sure,

I have tested with max MTU size like following:

GS108T set to 9216
PC set to 9k
NAS set to 9000

Max MTU size must decreased by the vlan tag, so to be sure i have tested with lower MTU size (8000, 5000, 4000, 2000 and 1800) for the nas.
PC cannot be configured with all this value, selected preconfigured value (MTU Disabled or 4k or 9k)

PC network card with Jumbo frames differents value works very fine in face of onather pc with Jumbo frames configured, the speed transfert for big files was increased by 57%.

vlan tags are 4 bytes, so your 9216 value should be good up to IP frames of 9194 (18 bytes for ethernet + 4 for vlan tag). So the modes that make sense are (a) set PC to 4K and NAS to 4000 or (b) set PC to 9K and NAS to 9000.

When you set it, does it fail somehow, or is it just not any faster?

If it's not any faster, you can probe the MTU with ping to make sure that the JF are getting through.

For instance,
ping NASIPADDRESS -f -l 8972

perhaps also try
ping NASIPADDRESS -f -l 8968

to account for the vlan tag. If those fail, find the largest value (after the -l) which works.

Hi StephenB,

It's just failed, any communication work between pc's and nas in any direction.

I have just do another try with MTU set to 4088 on RN104 and my PC, the GS108T set to 9216 MTU size and the result is failed.

ping is ok without command option but when i try to ping with -f -l 4088 or 4000 or 1500 is failed :(

ping -f -l 1472 succeeds?

(I subtracted 28 from the 9000 above for a reason).

Hi,

Sure the simple ping ip_address command is working and with -l 1472 also but web interface is accessible but not usable (like one http request on two passed correctly)

Well, the net is that despite the configuration settings the Jumbo frames aren't working along the path. Since you know its not the switch or the PC, that would imply a problem with the RN102.

ping -l 1472 means that the full 1500 byte MTU for ethernet is ok, but nothing else is working.

You are just using one NIC? Or is the RN104 set up for teaming?