Curious host names



  • My ISP provides host names based on the cable modem and firewall/router MAC addresses.  I have host names for both IPv4 & IPv6.  However, I have noticed something curious.  The IPv4 host name contains the MAC for the NIC connected to the WAN, but the IPv6 name contains the LAN MAC.

    Any idea why this might be happening?  DHCP is used for IPv4 and DHCPv6 for IPv6 and I have a /56 prefix.



  • @JKnott:

    My ISP provides host names based on the cable modem and firewall/router MAC addresses.  I have host names for both IPv4 & IPv6.  However, I have noticed something curious.  The IPv4 host name contains the MAC for the NIC connected to the WAN, but the IPv6 name contains the LAN MAC.

    Any idea why this might be happening?  DHCP is used for IPv4 and DHCPv6 for IPv6 and I have a /56 prefix.

    Ofcourse no need/sense to address/publish a WAN, just directly any LAN because IPv6 is public addressing and exposure ?



  • Either way, I have a host name for both IPv4 and IPv6 from my ISP, in addition to the LAN addresses I have configured on a public DNS server.  My question is why the WAN MAC is used for the IPv4 host name, but LAN MAC for IPv6.  Both resolve to the WAN IP addresses.

    I verified this by taking the addresses listed by ifconfig, with the WAN interface being re0 and LAN, bge0.  I then used the host command for both IPv4 and IPv6 addresses on re0 to obtain the host names provided by my ISP.


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