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How to insert DNS received from DHCPv6 into RDNSS in RA ?

Hi,

I have a router with G0/0 facing upstream, and getting DHCPv6 NA for G0/0 as well as DHCPv6-PD /56 which I use on G0/1 facing downstream, where I use SLAAC with a /64 from the PD for my laptop and other devices.

INTERNET------[G0/0] ROUTER [G0/1]------LAPTOP

SLAAC works fine with the PD prefix and I get connectivity as well as default gateway from the RA.

The problem is here: From DHCPv6 I also get IPv6 DNS servers (can see that from sh ipv6 dhcp interface below), and I cant seem to figure out how to automatically send the v6 DNS server I learn from DHCP into RDNSS automatically/dynamically to my device via SLAAC

The only way I can get v6 DNS to my laptop is by manually confiuring DHCPv6 server on the router and statically configuring the DNSv6 server in the pool and using the O-flag on G0/1.  Thats hardly dynamic !

ROUTER#sh ipv6 dhcp interface

Configuration parameters:
IA PD: IA ID 0x00050001, T1 166424, T2 266278
Prefix: 2000:DB8:100::/56
preferred lifetime 332848, valid lifetime 937648
expires at Dec 01 2015 06:48 AM (932311 seconds)
DNS server: 2000:DB8:200::6
Domain name: example.com
Prefix name: prefix-pd

int g0/1

ipv6 address prefix-pd ::1/64
ipv6 enable
ipv6 nd other-config-flag
ipv6 dhcp server dnspool

Anyone have any ideas ?

Im aware RDNSS was only in recent code. Should be able to run 15.x on my router

thanks

Mark

1 ACCEPTED SOLUTION

Accepted Solutions
VIP Advisor

What about if you add

What about if you add something like (untested):

ipv6 dhcp pool lan
  import dns-server

int gig0/1

  ipv6 dhcp server lan

2 REPLIES 2
VIP Advisor

What about if you add

What about if you add something like (untested):

ipv6 dhcp pool lan
  import dns-server

int gig0/1

  ipv6 dhcp server lan

spot on - thank you

spot on - thank you

worked like a charm on 151-4.M10

I also added import domain-name

ipv6 dhcp pool dnspool
 import dns-server
 import domain-name

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