如何使用Linux下的dhclient获取IPv6地址

dhclient 参数说明：

-6	Combined with only one of these switches:  -S -T -N
-S	Stateless Mode: Perform an information-only request over DHCPv6 to get stateless configuration parameters
-T	IA_TA
-N	IA_NA
-P	IA_PD
-g	For debugging. Set the giaddr field of all packets the client sends to the IP address specified.
-s <IP/FQDN>	Specify the server IP address or FQDN
-I <dhcp-client-identifier>
-H <host-name>	host-name option to be sent to the server
-V <vendor-class-identifier>	Specify the vendor-class-identifier option to send to the DHCP server.
-cf <config-file>

系统安装dhclient的时候给了一个config-file的模板，我们把这个模板copy到dhclient配置路径下，然后修改其内容

# cp /usr/share/doc/dhclient-4.2.5/dhclient6.conf.example /etc/dhcp/dhclient6.conf

# vi /etc/dhcp/dhclient6.conf

…..

script "sbin/dhclient-script";

interface "eth0" {

send dhcp6.client-id DUID;

send dhcp6.reconf-accept;

request;    

# request dhcp6.name-servers, dhcp6.domain-search;

}

注：这里的request是dhclient向DHCP服务器要求的options list，比如DNS，SIP服务器地址等等

然后我们通过命令行验证是否可以从DHCP服务器获得v6地址：

# dhclient -6 -d eth0                                                            //先release

# dhclient -6 -d -T -cf /etc/dhcp/dhclient6.conf

如果分配地址成功，可以用如下命令检查相关信息：

# more /var/lib/dhclient/dhclient6.leases

default-duid "\000\001\000\001 _\223\321\000\014)\331\017\203";

lease6 {

  interface "eth0";

  ia-na 29:d9:0f:83 {

    starts 1489934110;

    renew 3600;

    rebind 5760;

    iaaddr 2001:db8:ac:1e32::1 {

      starts 1489934110;

      preferred-life 7200;

      max-life 7500;

    }

  }

  option dhcp6.client-id 0:1:0:1:20:5f:93:d1:0:c:29:d9:f:83;

  option dhcp6.server-id 0:1:0:1:20:60:dd:ba:0:c:29:53:70:87;

  option dhcp6.name-servers 2001:db8::3,2001:db8::4;

}

 

如果希望开机以后自动通过DHCP获取v6地址，需要在网卡的配置文件里面增加相关配置

# vi /etc/sysconfig/network-scripts/ifcfg-eth0

# Enable DHCPv6-PD client.

DHCPV6C=yes

DHCPV6C_OPTIONS="-P -cf /etc/dhcp/dhclient6.conf"

# Disable make_resolv_conf function in /sbin/dhclient-script.

PEERDNS=no
 

然后重启网络服务

# service network restart