Cisco DHCPv6 Server Configuration

IPv6 DHCP configuration commands:
  default            Set a command to its defaults
  dns-server         DNS servers
  domain-name        Domain name to complete unqualified host names
  exit               Exit from DHCPv6 configuration mode
  import             Import options
  information        Information refresh option
  nis                NIS server options
  nisp               NISP server options
  no                 Negate a command or set its defaults
  prefix-delegation  IPv6 prefix delegation
  sip                SIP server options
  sntp               SNTP server options

R1(config-dhcp)#prefix-delegation ?
  X:X:X:X::X/  IPv6  x:x::y/
  aaa                 Acquire prefix from AAA
  pool                IPv6 prefix pool


i can see the command address prefix am using GNS3 7200 ios

Hi Rene,

Could be a stupid question though. How do the client devices get Default Gateway IP address in DHCPV6 configuration. I mean will it be always the link local ip address of that connecting interface of the Router to the LAN? I am bit confused …need your help…

Hi Ahammad,

With DHCPv6, we don’t advertise a default gateway. We use the router advertisements to figure out what router to use as the default gateway.

DHCPv6 is only used to supply IPv6 addresses and things like DNS, domain names, NTP servers, etc.




Which IOS version and Router you guys use? command ipv6 address dhcp is not available in my GNS3 implementation.

my IOS version is c7200-advipservicesk9-mz.152-4.S5.image & c3660-jk9o3s-mz.124-25d.image

I’ve seen before that these commands are not supported in these versions. My examples are done on 1841 or 2811 routers with the latest 15.x version or on Cisco Virl.

I managed to get this lab to work correctly with GNS3 1.5.2 and below IOS´s

BOOTLDR: 7200 Software (C7200-ADVIPSERVICESK9-M), Version 15.2(4)S5, RELEASE SOFTWARE (fc1)

BOOTLDR: 7200 Software (C7200-ADVENTERPRISEK9-M), Version 12.4(24)T5, RELEASE SOFTWARE (fc3)

BOOTLDR: 7200 Software (C7200-ADVIPSERVICESK9-M), Version 15.2(4)S5, RELEASE SOFTWARE (fc1)

Thanks for letting us know, Elliott!

Hi Rene,
With DHCP stateful Configuration, the client has got IPv6 2001:1111:1111:1111:255A:E159:32AF:5E42.
From where the client get the last 4 octet in the IP format?
i do not see FFFE so it does not EUI-64, How it get that?

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What is the operating system of the client, and what is the client’s MAC address? Some operating systems, Microsoft comes to mind, intentionally scramble the last few octets for the sake of privacy. The idea is that if the true EUI-64 standard is followed, then a client’s activity can tracked as well as traced back to the originating computer. Microsoft will not use the client’s MAC address for IPv6 addressing to safeguard privacy.

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19 posts were merged into an existing topic: Cisco DHCPv6 Server Configuration

Thank you Very Much Rene for your lessons.

One small configuration problem which I am facing in the IOU with ios 15.0 is as below, while trying to configure the stateful dhcp.

Router(config)#ipv6 dhcp pool STF
IPv6 DHCP configuration commands:
  default                              Set a command to its defaults
  dns-server                       DNS servers
  domain-name                Domain name to complete unqualified host names
  exit                                     Exit from DHCPv6 configuration mode
  no                                       Negate a command or set its defaults
  prefix-delegation          IPv6 prefix delegation
  sip                                      SIP Servers options

The option of configuring “address prefix” after configuring “ipv6 dhcp pool STF” do not appear. Is this a problem with IOU or am I missing some other configurations, which may be done prior to this. I am facing similar problem while trying to configure some of the other features also. May you be able to help me…

Hello Abey.

Others have had similar problems. It all depends on the version of IOS you’re using and the platform. Take a look at this post which includes some IOS versions and platforms on which it has been successfully implemented.

However, using your version it is possible to implement the same thing using the prefix-delegation command. If you’re interested, you can find out more information about that here.

I hope this has been helpful!


Thank you Laz. Your reply is most appreciated. Have a Great Day !!

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Hi Rene,

I am following your steps to configure ipv6 Stateful. But, seem there is no command "R1(config-if)#ipv6 address dhcp " on my router. I used 7206 and 3725

Hello Thanh

Take a look at this Cisco Command Reference for the command. Take a look at the IOS versions that support this command and compare with your devices…

Let us know what you find…

I hope this has been helpful!


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Hi Lazaros,

I am using ios ver 15.x Could you give me the correct command according through my ios ver ? Beside, please upgrade your steps to latest ios version though

Thank you!

Hello Thanh

After reviewing several features on the Cisco feature navigator, I come to the conclusion that several IOS versions and license levels (IPBASE, SECURITY, ADVANCED IP Services, Enterprise services etc) for different platforms do support the DHCPv6 feature and several do not. Because the 7206 is quite old, it may be a platform issue. As for the 3725 I was unable to find information about it in the feature navigator. In any case, I suggest you try to get access to an Advanced IP services IOS for your devices if possible. All IOS versions used in the lessons are up to date since this feature is avilable from the early 12.X versions.

I hope this has been helpful!


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In which scenario, we should use stateful and stateless DHCP. can you suggest?


Hello Nyi Nyi.

Remember that SLAAC provides only IPv6 address, subnet mask and default gateway. It does not provide DNS server IP addresses. This is insufficient for connectivity to the Internet where domain names are used such as for web pages for example. Stateless address autoconfiguration (SLAAC) is useful in situations where you require a more automated network connectivity. For example, a TV can automatically configure itself, gain access to Internet services using preconfigured IPv6 addresses instead of domain names, and provide preset services to the user without the need to configure any network parameters. The same may be true for printers that have the ability to be connected to the cloud and be accessible to your devices via the Internet without the need for extensive IPv6 configurations.

The whole idea behind SLAAC is to eliminate the need for human intervention in configuring the parameters of IPv6 connectivity or for configuring a DHCP server to provide those parameters. DNS is really useful only for humans, as it is easier to remember words rather than numbers to access a specific network resource. But if devices configure themselves, DNS is suddenly not as important.

I hope this has been helpful!


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Why in STATEFUL Active clients: 1

and in STATELESS Active clients: 0