What is the largest number of bytes I can send through one UDP send block packet using the UDP send block in the Beagle board support package?
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MathWorks Support Team on 27 Feb 2013
Using Embedded Linux with Beagle Board, what is the maximum number of bytes I can send in a single packet with the Send UDP block? Can't find any reference to it in the documentation but when I try to send 2000 bytes (1000 16 bit words) Wireshark indicates it's getting fragmented.
MathWorks Support Team on 29 Jun 2022
Edited: MathWorks Support Team on 29 Jun 2022
The packet fragmentation limit depends on the Maximum Transfer Unit (MTU)
value set for LAN the customer is using. That is MTU is a mutually agreed
value in between all the computers, routers, switches in a LAN. The
following command displays MTU setting for the BeagleBoard:
eth0 Link encap:Ethernet HWaddr 9a:73:16:80:18:6a
inet addr:172.28.145.93 Bcast:172.28.145.255 Mask:255.255.255.0
inet6 addr: fe80::9873:16ff:fe80:186a/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1488 Metric:1
RX packets:37368657 errors:0 dropped:0 overruns:0 frame:0
TX packets:43107080 errors:0 dropped:0 overruns:0 carrier:0
RX bytes:2299134916 (2.2 GB) TX bytes:209271720 (209.2 MB)
Note that the default MTU is 1488 as seen above. One can change the MTU
value of a Linux system by using ifconfig command as explained in the
However, do note that this is no guarantee that UDP packets will not be
fragmented. The routers /switches in the LAN network can fragment UDP
packets even if it is transmitted at full size on the BeagleBoard.