Should mac address be case sensitive?

  • Hello,

    I am on 2.3.1-RELEASE-p1 of pfsense.

    I have been attempting to set a static dhcp entry for a new computer on our network and have "Deny Unknown Clients" enabled on the network.  I was unable to get pfsense to grant an IP address to the new computer.  Windows had reported the mac in all caps and I had entered it that way without thinking.  After attempting to get an IP using a live Linux USB, I looked again at the mac address and saw that Linux was reporting the letters of the mac in lower case.  Since I didn't have anything to lose I made the change in pfsense's dhcp server page to the mac address and then the machine was immediately granted an IP.

    Should mac addresses be case sensitive since they just represent hex digits?



  • I think that's just a Unix thing, even though FreeBSD isn't technically Unix. It just treats upper case letters as a different character from its lower case counterparts. So, my theory is that it was just an oversight and that it shouldn't be case sensitive but I may be wrong.

  • In theory, no a MAC address shouldn't be case-sensitive. Many things are case-sensitive in *nix OSes though. dhcpd apparently requires them in all lower case to match.

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