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analogdevicesinc / rfsom-box-gui

GUI application for the RFSOM Box
GNU General Public License v2.0
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Fix TAP IP fragmentation issue #2

Closed emaclean-adi closed 6 years ago

emaclean-adi commented 7 years ago

The TAP interface did not work because the extra overhead from Ethernet reduced the effective MTU. The MTU of the IP layer defaults to 1500 bytes which is all that our MAC can handle, leaving no room for Ethernet overhead. When fragmenting IP packets larger than MTU, the fragmentation offset of the fragmented packet would be set incorrectly when using TAP. Reducing the MTU of the adi_radio device to allow for the Ethernet overhead allows fragmented IP packets to be sent correctly.

This update lowers the MTU of adi_radio by 10 bytes and also enables TAP instead of TUN and also enables encryption.

emaclean-adi commented 7 years ago

It might need to be 18 bytes rather than 10 though I haven't seen any problems with using 10

rgetz commented 7 years ago

Thanks - this makes perfect sense - I think there are just some things that crept into the fix by mistake.

rgetz commented 7 years ago

Although I'm the worse for doing the same - one commit fixes one issue.

This should be split into two commits.