Hello,
I’m working on a project that involves Beaglebone Black Rev.C’s sending large UDP packets (>4000 bytes) to a local PC using ETH0.
The network switch and receiving PC support Jumbo Frames (>= 9kb) and it would be very helpful if the Beaglebones did too. As far as I can tell, the MTU limit is 1500 byte on the Beaglebones.
I have been looking into the BB Enhanced, which features Gigabit ethernet, and wonder if it could support Jumbo Packets, if in fact the Black Rev. C cannot.
For reference, I’m running BeagleBoard.org Debian Image 2018-01-28, 4.9.78-ti-r94
So my question is, what determines the MTU limits on the Beaglebone Black? Is it possible to increase it on either the Black or on the Enhanced?
My knowledge on the I’m trying to get a better understanding, so any help is appreciated.
debian@bbb-pwr01-ser09:~$ sudo ip link set eth0 mtu 1600
Error: mtu greater than device maximum.
debian@bbb-pwr01-ser09:~$ ip link show | grep eth0
4: eth0: <BROADCAST,MULTICAST,DYNAMIC,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
debian@bbb-pwr01-ser09:~$ uname -r
4.19.94-ti-r64
A quick scan of the CPU used on the BBB leads me to believe that it may not support jumbo frames. The AM335x Stiara has an embedded 2 port switch and the TI data sheet lists the switch as only having 8K bytes of buffer (packet memory). I see no mention in any of TI’s doc’s for jumbo frame or even for a place to set the MTU (PDU size) .