如何配置centos dhcp server， 以便可以在dhcp offer, ack 帧返回 option 61信息

giantbull

如何配置centos dhcp server， 以便可以在dhcp offer, ack 帧返回 option 61信息, 我在dhcpd.conf 添加了如下选项，为何不起作用

if exists dhcp-client-identifier {
  option dhcp-client-identifier = option dhcp-client-identifier;
}

giantbull

dhcpd.conf 如下所示，请高手指点

#
# DHCP Server Configuration file.
#   see /usr/share/doc/dhcp*/dhcpd.conf.example
#   see dhcpd.conf(5) man page
#
option domain-name "linuxidc.local";

option domain-name-servers 192.168.188.11, 192.168.188.12;

default-lease-time691200;

max-lease-time691200;

if exists dhcp-client-identifier {
  option dhcp-client-identifier = option dhcp-client-identifier;
}

subnet 192.168.188.0 netmask 255.255.255.0 {

  range 192.168.188.100 192.168.188.159;

  range 192.168.188.170 192.168.188.253;

  default-lease-time 259200;

  max-lease-time 259200;

  option routers 192.168.188.2;

}

subnet 192.168.189.0 netmask 255.255.255.0 {

  range 192.168.189.100 192.168.189.253;

  option routers 192.168.189.2;

}

host printer1 {

  hardware ethernet 00:12:34:56:78:90;

  fixed-address 192.168.188.111;
}