IPv6 Stateless Configuration


   First time poster here. I would just like to ask what are the flags on
router advertisement to enable a host to autoconfigure its IPv6 address.
There is this device that I'm configuring that I cant get RA to work. I was
able to work out the connectivity from the device to the IPv6 internet, but
the problem is host behind this device is not getting its unique global ipv6
address. The device is a cyberoam UTM.

Thanks! Rod Bio.

You need all to be part of the same Ethernet network. So if this UTM can act as a bridge/switch you should be ok. Otherwise the RA broadcasts need to reach your device so it guesses the network and add it's Mac address to the network and make an ipv6 address.

I would say RA is a bit like DHCP in your case in terms of network topology but beside that RA is simpler (no leases table).

Toute connaissance est une réponse à une question

That's my setup right now. The problem is the machine is not configuring its
IPv6 address with RA already turned on. I'm guessing that the flag set on
the UTM router advertisement messages is wrong. May I know the default flags
use on a cisco router? Thanks.

The default is that M and O bits are off, ie hosts should do SLAAC and there is no DHCPv6 info to be had.

I have seen layer 2 devices not forwarding IPv6 packets (while forwarding IPv4 packets)...

I would put a packet capture, and see if I see the RA packets coming from the router.

On a Cisco router, RA is enabled by default and does not require any setting.

Pay attention to the special layer 2 multicast address for the RA packet.

Got it now. The preferredlifetime should be less than the value of the
validlifetime option. Thanks BTW! :smiley: