IPv6 UUID-like Strings in IPv4 DHCP Leases MAC Fields


  • Hi Everyone,

    I am observing a very strange situation with my pfSense setup. I recently had Microsoft's DirectAccess(DA)/VPN set up in Vultr (cloud) and it was working not too badly.

    We've now moved our DA/VPN to an on-premise ESXi box and that's when the weirdness started happening. Clients can connect fine remotely but I observe what appears to be IPv6 "UUID-like" strings in the IPv4 DHCP leases.

    Any thoughts why the pfSense DHCPv4 server is accepting weird MAC address entries?

    pfSense 2.4.4p3 (AMD64)

    Thanks in advance!

    DHCP Lease Weirdness - Redacted.png


  • DHCPv4 can use a "client identifier" such as a DUID, just like DHCPv6. (rfc4361)

    I suspect this is what you are seeing.