How to configure ipv6 with slaac+dhcpv6 stateless

Installing and Using OpenWrt Network and Wireless Configuration
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how to configure ipv6 with slaac+dhcpv6 stateless

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Network

config interface 'lan'
        option proto 'static'
        option device 'eth0.3'
        option netmask '255.255.255.0'
        option ipaddr '192.168.1.1'
        option delegate '0'
        list ip6class 'wan6'
        option ip6assign '64'

DHCP

config dhcp 'lan'
        option leasetime '12h'
        option interface 'lan'
        option start '100'
        option limit '150'
        option dhcpv4 'server'
        option dhcpv6 'server'
        option ra 'server'
        option ra_slaac '1'
        list ra_flags 'managed-config'
        list ra_flags 'other-config'
2 Likes
3

Should be 0 for stateless.

2 Likes
4

My bad, I got that config from a device that needed prefix delegation.

1 Like
5

Using this setting will still generate an address similar to dhcpv6

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I suppose you saw that in the packet capture you just took from the router?

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RA FLAG:
ra-flag

CLIENT REQ

dhcp-r
dhcp-r592×783 15.8 KB

ROUTER ACK
dhcp-a

The client WIN10 got the ipv6 of 2*:::550::395

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This is not a request, but a confirm. Basically your client keeps the IP.

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The RA flags are only advice to clients what the router supports. A client can make a DHCPv6 request even if the RA flag is zero-- a client doesn't have to look at RA packets at all.

I think the only way to make udhcpd not issue stateful DHCPv6 addresses upon request is to disable the DHCPv6 function entirely. At least that is all that the documentation suggests.

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Yes, then it is not possible to get dns only from DHCPV6 to maintain compatibility. The M flag is useless

11

As said above, there is actually a whole DHCPV6 interaction

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RA can contain nameserver information No need for dhcpv6 if nameserver is the only thing you want or need.

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Yes, I mean for better compatibility

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You could install radv and configure dnsmasq only for stateless dhcpv6 and disable RA. radvd could then send RA as you desire? But AFAIK this can not be configured with UCI.

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Adding dhcpv6_na='0' in the dhcp configuration file can realize not assigning IANA