Configuring the DHCPv6 Local Server

In addition to the embedded DHCP local server that is used for IP version 4 (IPv4) address support, E Series routers include an embedded DHCPv6 local server. This server enables the router to function as a server for the DHCP protocol for IP version 6 (IPv6). The DHCPv6 local server sends and receives packets through IPv6 and informs IPv6 of the routing requirements of the router clients.

The DHCPv6 local server provides the following IPv6 address support:

Note: The DHCPv6 local server supports the DHCPv6 Rapid Commit option (DHCPv6 option 14). When a DHCPv6 client includes the DHCPv6 Rapid Commit option in the Solicit messages, the server recognizes this option and the client terminates the waiting process as soon as it receives a Reply message with the Rapid Commit option from the server. The server and client then use a two-message exchange (Solicit and Reply) to configure clients, rather than the default four-method exchange (Solicit, Advertise, Request, and Reply). The two-message exchange provides faster client configuration, and is beneficial in environments in which networks are under a heavy load.

Use the following steps to configure the DHCPv6 local server:

  1. Enable the DHCPv6 local server.
    host1(config)#service dhcpv6-local
  2. Specify the IPv6 prefix and lifetime that are to be delegated to the DHCPv6 client. The specified prefix is delegated by the DHCPv6 local server when requested by the client.
    host1(config-if)#ipv6 dhcpv6-local delegated-prefix 2001:db8:17::/48 lifetime infinite

    Use the lifetime keyword to specify the time period for which the prefix is valid. This lifetime overrides the default lifetime that is set in Global Configuration mode. If no lifetime is specified, the default lifetime is assigned.

    • Specify the number of days and, optionally, the number of hours, minutes, and seconds. You cannot specify a lifetime of zero (that is, you cannot set the days, hours, minutes, and seconds fields all to zero).
    • Use the keyword infinite to specify a lifetime that does not expire.
  3. Specify the name of a DNS domain for DHCPv6 clients in the current virtual router to search. You can specify a maximum of four DNS domains for a DHCPv6 local server’s search list.
    host1(config)#ipv6 dhcpv6-local dns-domain-search xyzcorporation.com host1(config)#ipv6 dhcpv6-local dns-domain-search xyzcorp.com
  4. Specify the IPv6 address of the DNS server and to assign the server to the DHCPv6 clients in the current virtual router. You can specify a maximum of four DNS servers.
    host1(config)#ipv6 dhcpv6-local dns-server 2001:db8:18::
  5. Set the default lifetime for which a prefix delegated by this DHCPv6 local server is valid. This default is overridden by an interface-specific lifetime.
    host1(config)#ipv6 dhcpv6-local prefix-lifetime infinite
    • Specify the number of days and, optionally, the number of hours, minutes, and seconds. You cannot specify a lifetime of zero (that is, you cannot set the days, hours, minutes, and seconds fields all to zero).
    • Use the keyword infinite to specify a lifetime that does not expire.
  6. Specify the DHCP unique identifier (DUID) type to be used in the communication between the DHCPv6 local server and clients. You can configure the type of DUID to be either Type 2 or Type 3. These two types are currently supported by the DHCPv6 local server application in JunosE Software. The Type 1 DUID is not supported by JunosE Software.
    host1(config)#ipv6 dhcpv6-local duid-type 3
  7. (Optional) Specify the maximum number of IPv6 prefixes that the DHCPv6 local server can delegate to each ATM interface, Ethernet subnet, VLAN interface, or POS access interface, or to a particular interface of subinterface. For more information about the limiting of delegated IPv6 prefixes, see Limiting the Maximum Number of IPv6 Prefixes Delegated Per Interface by the DHCPv6 Local Server Overview.
    • To set the maximum number of IPv6 prefixes globally for an interface type:
      host1(config)#ipv6 dhcpv6-local limit vlan 300
    • To set the maximum number of IPv6 prefixes for a particular interface:
      host1(config)#ipv6 dhcpv6-local limit interface gigabitEthernet 6/0 500
  8. (Optional) Enable the DHCPv6 local server to send a Delegated-IPv6-Prefix with the PPPv6 interface name to the SRC client after delegating the IPv6 prefix to the CPE. The SRC client sends the Delegated-IPv6-Prefix to an SRC server.

    By default, the DHCPv6 local server does not send the Delegated-IPv6-Prefix to the SRC client. For more information about this feature, see Sending of Delegated-IPv6-Prefix from the DHCPv6 Local Server to SRC Client Overview.

    host1(config)#sscc enable cops-prhost1(config)# sscc protocol ipv6host1(config)#ipv6 dhcpv6-local sscc enable

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