dhcpcd-discuss

Hi Renu

On 19/06/2017 11:27, Renu Bansal wrote:
> I am getting an issue while configuring  my device with stateless DHCPv6
> server. I need to receive SLAAC address from RA and other configuration
> from DHCPv6 Server
> 
> Following is my setup's configuration:
> 
> Server:
> 
> ·         Windows Server 2012 R2
> 
> Client:
> 
> ·         dhcpcd v6.11.0, and
> 
> ·         linux kernel: v2.6.32
> 
>  
> 
> Currently  Network Router is configured to send RA packets with
> following bit configurations:
> 
> M-bit: 0
> 
> O-bit: 1
> 
>  
> 
> Currently we are getting both IPv6 address assigned by DHCPv6 server as
> well as one from SLAAC. but i think as per M Bit Configuration, DHCPv6
> address should have been ignored.

O and M are just hints about what the default DHCPv6 client should do.
You can override this in dhcpcd.conf

> Could you please suggest parameters to be added in conf file for
> configuring dhcpcd6.11.0 to use SLAAC. Also, please tell me if this
> behaviour could be due to some missing configuration of older linux
> kernel version.

The stock dhcpcd.conf should work fine
Saying that, 6.11.0 is old and you should upgrade to 6.11.5, or ideally
try dhcpcd-7.0.0-rc1 if here are still problems for you.
Your kernel is still quite old, 2.6 is positively ancient!
dhcpcd should still set SLAAC correctly though.
Be warned that dhcpcd does try to support newer IPv6 setups in Linux and
I've not tested with an old kernel for a very long time.

> To avoid IPv6 configuration from DHCPv6, there can be two possible ways:
> 
> 1. DHCP request omits 'IANA' field, so as not to get back the address.

Yes.
dhcpcd will do this on stock config if the O bit is set.

> 2. Address is received from DHCPv6 but is ignored by the dhcpd client.
> 
> (Could you let me know which of the above would be the case for
> Stateless DHCP)

I'm not sure dhcpcd supports this.
If there is an address in the reply, dhcpcd will try to use it.
But the server won't make up an IAID ... so if dhcpcd didn't request an
address the server shouldn't set one.

Roy