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@dbauer@social.caserio.de

2026-05-28 19:26 UTC

Funny chasing bugs like the Hardware MAC not properly setting UDP package checksum, which lead to DHCP to work in 1/3 networks

Replies (1)

  • @dbauer@social.caserio.de 2026-05-28 20:39

    It definetly feels good to manually verify my hardware working with my custom Ethernet Firmware to isolate the issue to LwIP. I could definetly capture some nice wireshark screenshots of "invalid" DHCP packages being sent with a checksum of 0 for my bachelor thesis. I now know, that isc-dhcp-server(on pfsense) accepts these DHCP requests, unbound-DHCP(on OPNsense) doesn't and whatever a generic GLinet router uses also doesn't accept it. #microcontroller #electronics

    Open ##4978657