DDNS conflict resolution - BlueCat Address Manager - 9.4.0

When a DHCP server is configured to distribute IPv4 and IPv6 leases, DDNS conflicts can occur when a host that's using the same hostname for both IPv4 and IPv6 networks receives an IPv4 address and attempts to receive an IPv6 address, or vice versa. The host fails to receive the other IP address type, as a "guard" record exists for that host record. To resolve the issue, you must configure the following DHCP Service options:

• Update Conflict Detection—when this option is enabled, the server will perform standard DHCID multiple-client, one-name conflict detection. Add this as a DHCP Service option set to Enabled.
  Attention: You must only configure the Update Conflict Detection Service option at the configuration, server group, and server levels.
• DDNS Dual Stack Mixed Mode—enables Dual-Stack Mixed Mode rules to be used for DDNS conflict resolution. Add this as a DHCPv4 and DHCPv6 Service option set to Enabled.
  Attention: The DDNS Dual Stack Mixed Mode Service option is only configurable at the configuration, server group, and server levels.
• DDNS Update Style—defines the DDNS update style when a DHCP server performs a DDNS update for a client. When the DHCP server performs a DDNS update for the client, an additional "guard" (either TXT or DHCID) record is added to DNS to record the DHCID of the client that owns the DNS entry. The update style can be either standard or interim. DHCP servers using standard update style create DHCID "guard" records and servers using interim update style create TXT "guard" records. Add this as a DHCPv4 and DHCPv6 Service option to ensure that the type of guard record remains the same for a given protocol. You must configure DHCPv4 and DHCPv6 to use different DDNS update styles.
  Attention: The DDNS Update Style Service option is only configurable at the configuration, server group, and server levels.
• DDNS Other Guard Is Dynamic—defines whether the presence of a DHCID "guard" record that was produced using a different DDNS update style allows a DNS entry to be overwritten. Exercise caution when enabling this option, as this option can result in entries that would otherwise be protected as static to be overwritten. Add this as a DHCPv4 and DHCPv6 Service option set to Enabled.
  Attention: The DDNS Other Guard Is Dynamic Service option is only configurable at the configuration, server group, and server levels.

When a DHCP server is servicing IP addresses to multiple networks or subnets and hosts move between wired and wireless networks, the DNS host record may not be updated as an existing "guard" record exists for that host for an IP address on a different subnet. To resolve the issue, you must configure the following DHCP Service options:

• Update Conflict Detection—when this option is enabled, the server will perform standard DHCID multiple-client, one-name conflict detection. Add this as a DHCP Service option set to Enabled.
  Attention: You must only configure the Update Conflict Detection Service option at the configuration, server group, and server levels.
• DDNS Guard ID Must Match—defines whether a client ID within a DHCID resource record must match the client ID of a DNS update to permit DNS entries associated to that DHCID record to be overwritten. Exercise caution if disabling this option, as disabling this option allows any DNS updater to replace DNS entries that have an associated DHCID resource record regardless of client identity. Add this as a DHCP Service option set to Disabled.
  Attention: The DDNS Guard ID Must Match Service option is only configurable at the configuration, server group, and server levels.