This notification signifies that the number of available IPv6 addresses for a particular prefix or link has fallen below the value of cnrdhcpv6Threshold. This notification signals a shortage of addresses. The shortage will continue until the number of free addresses has reached or exceeded the threshold specified by cnrdhcpv6Threshold. This notification will only be generated when the shortages of IPv6 addresses is first encountered. When ciscoNetRegDhcpv6AddressShortageStop is generated, it enables this notification to trigger again the next time the number of free addresses for that prefix or link falls below the value indicated by cnrdhcpv6Threshold. At the time this event is triggered, cnrdhcpv6LinkName indicates the name of the link or prefix, cnrdhcpv6FreeAddressValue provides the count of the addresses, cnrdhcpv6Threshold indicates the configured percentage that was crossed. In case cnrdhcpv6ThresholdType is of type 'prefix' then cnrdhcpv6PrefixAddress and cnrdhcpv6PrefixLength indicate the address and length of the prefix and cnrdhcpv6TypeDesc indicates extra grouping information on the prefix or link that triggered this event.