Status: DHCPv6 leases



  • why now version have no show any records in Status: DHCPv6 leases ?

    my client computer online in LAN. why it isn't show in DHCPv6 leases ?



  • Rebel Alliance Developer Netgate

    Did it actually do DHCPv6? Or did it do SLAAC?

    Many things will do SLAAC but have no DHCPv6 client, or DHCPv6 may not be enabled on the client.

    Check the client's interface config (ipconfig in windows, etc) to see if it's really reporting that its v6 IP was obtained via DHCP.



  • I am sure client config auto get ipv6 address via pfsense DHCP. but pfsense DHCP has no show any informations.

    DHCP v4 show normal online. DHCP v6 has no show any.







  • Rebel Alliance Developer Netgate

    In assisted mode, the client can still do SLAAC and not just DHCPv6. To force DHCPv6 and no SLAAC, you want "Managed".

    Without seeing the address info from the client, you can't tell how they obtained their IP, the pfSense can't really tell you that part (especially if they did SLAAC)



  • @jimp:

    In assisted mode, the client can still do SLAAC and not just DHCPv6. To force DHCPv6 and no SLAAC, you want "Managed".

    Without seeing the address info from the client, you can't tell how they obtained their IP, the pfSense can't really tell you that part (especially if they did SLAAC)

    if I setup to Managed mode,then the andriod system client can't get ipv6 network. So I am setup to assisted mode.

    the photo is windows 7 chinese system client.




  • Copied from (with some modifications): DHCPv6 - Understanding of address configuration in automatic mode and installation of DHCPv6 Server

    An IPv6 host performs stateless address autoconfiguration automatically and uses a configuration protocol such as DHCPv6 based on the following flags in the Router Advertisement message sent by a neighboring router:

    Managed Address Configuration Flag:
    Also known as the M flag. When set to 1, this flag instructs the host to use a configuration protocol to obtain stateful addresses.

    Other Stateful Configuration Flag:
    Also known as the O flag. When set to 1, this flag instructs the host to use a configuration protocol to obtain other configuration settings.

    Combining the values of the M and O flags can yield the following:

    Both M and O Flags are Set to 0: (pfSense: Unmanaged)
    This combination corresponds to a network without a DHCPv6 infrastructure. Hosts use router advertisements for non-link-local addresses and other methods (such as manual configuration) to configure other settings.

    Both M and O Flags are Set to 1: (pfSense: -)
    DHCPv6 is used for both addresses and other configuration settings. This combination is known as DHCPv6 stateful, in which DHCPv6 is assigning stateful addresses to IPv6 hosts.

    The M Flag is Set to 0 and the O Flag is Set to 1: (pfSense: Assisted)
    DHCPv6 is not used to assign addresses, only to assign other configuration settings. Neighboring routers are configured to advertise non-link-local address prefixes from which IPv6 hosts derive stateless addresses. This combination is known as DHCPv6 stateless: DHCPv6 is not assigning stateful addresses to IPv6 hosts, but stateless configuration settings.

    The M Flag is Set to 1 and the O Flag is Set to 0: (pfSense: Managed)
    In this combination, DHCPv6 is used for address configuration but not for other settings. Because IPv6 hosts typically need to be configured with other settings, such as the IPv6 addresses of Domain Name System (DNS) servers, this is an unlikely combination.

    Maybe someone from the developers involved in the IPv6 code could comment why pfSense uses the M and O flags mutually exclusive. Before looking at the code I thought that the Managed case would have both M and O flags set.



  • @bardelot:

    Both M and O Flags are Set to 1: (pfSense: -)
    DHCPv6 is used for both addresses and other configuration settings. This combination is known as DHCPv6 stateful, in which DHCPv6 is assigning stateful addresses to IPv6 hosts.

    Maybe someone from the developers involved in the IPv6 code could comment why pfSense uses the M and O flags mutually exclusive. Before looking at the code I thought that the Managed case would have both M and O flags set.

    That would of course explain why IPv6 DHCP never worked as expected here, an I had to manually assign IPv6 addresses and DNS entries to all my hosts.


  • Rebel Alliance Developer Netgate

    Android has no DHCPv6 client! It can only do SLAAC.



  • The problem you have is that when you enable the Managed mode radvd will be configured to not allow autonomous address configuration (AdvAutonomous off) on the subnet. Maybe you could try to change that to "AdvAutonomous on" such that clients that do not have a DHCPv6 client will fallback to stateless configuration?


  • Rebel Alliance Developer Netgate

    That's what Assisted mode does, more or less.

    The OP's original problem is that the client didn't in DHCP leases, yet had an IPv6 IP.

    The problem is that he's testing an Android client, which has no DHCPv6 client, so it only does SLAAC.

    That's why it doesn't show in the DHCP leases, because it didn't get an IP from DHCP. Mystery solved.


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