DHCPv6 is a method to assign IPv6 addresses automatically to network clients. When you enable IPv6 for a trusted or optional interface, you can enable the DHCPv6 server on the interface, to assign IPv6 addresses to clients that connect.
Before you can enable the DHCPv6 server, you must enable IPv6 for the interface. For more information, see Enable IPv6 for a Trusted or Optional Interface.
You cannot use these special purpose IP addresses in the DHCPv6 configuration:
You can enable DHCPv6 for a trusted or optional interface that has IPv6 enabled.
To reserve a specific IP address for a client:
To get IPv6 addresses from a server, the DHCPv6 client can use a rapid two-message exchange (solicit, reply) or a four-message exchange (solicit, advertise, request, reply). By default, the DHCPv6 client uses the four-message exchange. To use the two-message exchange, you must enable the Rapid Commit option on the XTM device and on the client. Select the Rapid Commit check box to enable the DHCP server to use the rapid two-message exchange to assign an IP address.
The IPv6 lifetime settings control the length of time an assigned IPv6 address remains valid and the length of time the address is preferred. To change the default lifetime settings. change the values for Valid Lifetime and Preferred Lifetime. The Valid Lifetime must be greater than or equal to the Preferred Lifetime.
By default, when it is configured as a DHCP server, your XTM device gives out the DNS and WINS server information configured on the Network Configuration > WINS/DNS tab. To specify different information for your device to assign when it gives out IPv6 addresses, you can add DNS servers in the DHCPv6 settings for the interface.
To configure DNS servers:
You can add the IP addresses of up to three DNS servers.
You can add the IPv6 addresses or domain name of SIP servers to your DHCPv6 server configuration. This enables the DHCPv6 server to provide the SIP server domain name or SIP server IP addresses to SIP clients that request them. You can specify a SIP server domain name, and up to three IP addresses.
To configure SIP servers:
Enable IPv6 for a Trusted or Optional Interface