[DHCP] how to send multiple prefixes in DHCP advertise

Atul Gupta atul14.kumar at gmail.com
Thu May 24 13:41:13 UTC 2012

I am using dhcpv6 server on my linux box and following is my config file :-

# vi /etc/dhcpd_v6.conf
# IPv6 address valid lifetime
#   (at the end the address is no longer usable by the client)
#   (set to 30 days, the usual IPv6 default)
default-lease-time 2592000;

# IPv6 address preferred lifetime
#   (at the end the address is deprecated, i.e., the client should use
#    other addresses for new connections)
#  (set to 7 days, the  usual IPv6 default)
preferred-lifetime 604800;

# T1, the delay before Renew
#  (default is 1/2 preferred lifetime)
#  (set to 1 hour)
option dhcp-renewal-time 3600;

# T2, the delay before Rebind (if Renews failed)
#  (default is 3/4 preferred lifetime)
#  (set to 2 hours)
option dhcp-rebinding-time 7200;

# Global definitions for name server address(es)
option dhcp6.name-servers 2001:05b0:3e1a:800a:0280:aeff:fe4b:0277;
option dhcp6.name-servers fd0d:edc3:e12a:0000::1;

# Set preference to 255 (maximum) in order to avoid waiting for
# additional servers when there is only one
option dhcp6.preference 255;

# Server side command to enable rapid-commit (2 packet exchange)
option dhcp6.rapid-commit;

#subnet definition for interface 1
subnet6 2001:05b0:3e1a:800a::/63 {
   prefix6 2001:5b0:3e1a:800b:: 2001:5b0:3e1a:800b:: /64;

I want to send multiple prefixes in DHCP advertise msg so i added one
more prefix next to existing one like this :-

subnet6 2001:05b0:3e1a:800a::/63 {
   prefix6 2001:5b0:3e1a:800b:: 2001:5b0:3e1a:800b:: /64;
   prefix6 fd0d:edc3:e12a:0001::  fd0d:edc3:e12a:0001:: /64 ;


But it's not working DHCP server is picking only the first prefix i.e.
2001:5b0:3e1a:800b:: /64
Can i send multiple prefixes in a single advertise msg if so how ?

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