[Dnsmasq-discuss] Sending RA without dhcp-range
simon at thekelleys.org.uk
Fri Jan 17 14:32:45 GMT 2014
On 17/01/14 14:21, Shixiong Shang wrote:
> Hi, Simon and Albert:
> Thank both of you for quick response!
> According to the man page online, the mode like “ra-only”, and
> “ra-stateless” are only used as part of “dhcp-range” option. However,
> this will also turn dnsmasq to DHCPv6 server, which I try to avoid.
It confusing, I agree but
_doesn't turn on the DHCPv6 server, and least for that prefix, and
turns on the DHCPv6 server only to replt to information-requests, not
> Would you please help me clarify how I can send RA on specific
> interfaces with the right flags? The only thing I can think of is
> leveraging “—ra-param”, but it doesn’t have place to put in mode
> Thanks again!
> On Jan 17, 2014, at 5:49 AM, Simon Kelley <simon at thekelleys.org.uk>
>> On 17/01/14 06:10, Albert ARIBAUD wrote:
>>> Le 17/01/2014 05:30, Shixiong Shang a écrit :
>>>> Hi, experts:
>>>> Is it possible that dnsmasq can send out RA with either A=0,
>>>> MO=1 (i.e. for DHCPv6 Stateful), or AO=1, M=0 (i.e. for DHCPv6
>>>> Stateless) WITHOUT dhcp-range? What I am trying to achieve here
>>>> is using dnsmasq to send out RA to trigger DHCPv6 Stateful or
>>>> DHCPv6 Stateless mode without acting as DHCPv6 server. Based on
>>>> my reading, I am under the impression that “—enable-ra” must be
>>>> used with “—dhcp-range”. Otherwise, dnsmasq will not send
>>> You are right about having to add enable-ra.
>>> However there is a syntax of dhcp-range which will not cause
>>> As per 'man dnsmasq' (search for 'dhcp-range'), the possible
>>> modes for IPv6 ranges include 'ra-only', which will previsely
>>> enable RAs without enabling any DHCP.
>> Neither of you are completely right.
>> enable-ra causes RA with A=0 and M = 1 O = 1 on every interface
>> that's doing DHCP, just to instruct the clients to do stateful
>> DHCP. It's intended as a simple option for systems which don't use
>> RA at all.
>> You don't need to set enable-ra at all to do RA on specific
>> interfaces with other flag combinations, ie
>> ra-only A=1 M=0 O=0 slaac A=1 M=1 O=1 ra-stateless A=1 M=0 O=1
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