Is pfSense corrupting my radius IPV4 checksum requests?



  • I am getting bad checksums on packets to the radius server's for authentication at the captive portal.  I have already disabled IP Checksum offloading to no avail.   This is the second system I have brought up.  The first was on a virtual platform with no issues.  The second was a standalone ibm platform.

    I have compared packet captures on the working machine to verify the checksum errors are not present.

    Anyone seen this before?


  • Rebel Alliance Developer Netgate

    What is showing you that there are bad checksums?

    And are the bad checksum values actually incorrect, or 0?



  • The Checksum is zero.

    I went down this route since radius was showing:

    krb5_g_i_t_w_p failed: Decrypt integrity check failed


  • Rebel Alliance Developer Netgate

    If the checksum is zero, the NIC that captured the packet must have been doing checksums in hardware. That's the only way it will be set to 0 that I'm aware of.

    If they were corrupt they'd have some other incorrect (or byte-swapped) value in there.



  • Do you think this is a red herring (only showing up in the capture) or really the issue?  I didnt do a capture on the radius side.  Just did it though pfsense.  I think I am going to give up on this hardware platform and try something different.


  • Rebel Alliance Developer Netgate

    I'm not familiar with the error to say for sure. Typically unless a checksum is non-zero and wrong, it's not worth worrying about. It's probably a red herring and not the root cause.

    To know more you'd have to capture on the other side.



  • 0 checksum would just be hardware checksum offloading. Can capture from the destination to get the checksum that's actually on the wire.


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