[Cerowrt-devel] shaggy dog story on 3.8.8-4 experiences
mcr at sandelman.ca
Thu May 16 15:21:53 EDT 2013
>>>>> "Steven" == Steven Barth <cyrus at openwrt.org> writes:
Steven> I was on holiday until yesterday so my reply is a bit late.
Thank you for the reply!
>> which means that any subnet that isn't allocated anywhere does not
>> result in a routing loop. It also causes the 6relayd to assign prefixes
>> to each interface.
>> I will see if I can hack on 6relayd, because I really like this.
Steven> This is actually done by netifd, not 6relayd. 6relayd is the
Steven> used in OpenWrt trunk (CeroWrt uses dnsmasq here I think) and provides most
Steven> of the homenet functionality (RFC 6204 should be pretty much covered by
Steven> OpenWrt with very few exceptions - I think only one)
okay, I see. I would have thought that since the prefix came down via
DHCPv6, that this was being done there too. I will read through netifd.
>> >> At least one prefix is behind another router, so this router can not
>> >> see that prefix is already in use. Suggestion: start at highest
>> >> number available and work downwards.
Dave> Two interior prefix allocation methods have been described by the
Dave> homenet and hipnet rfcs. openwrt follows neither at present.
>> sure, that's not the point. The point is that the set of "prefixes in
>> use" is not limited to just those on local interfaces, but also ones
>> that might have a static route elsewhere. Yes, I agree that routing
>> protocols are important and useful... that's why I have 4x 3800 now for
>> play and testing :-)
>> The incidence of conflict would be less if the auto-assigned numbers
>> started from highest number. At least for me, it would.
Steven> That's imo not a good idea because it doesn't really solve the issue.
I understand... I wasn't suggesting it would solve the problem, just
make it less of a toe stumbing event.
Steven> I could modify the assignment logic in netifd to scan through all ip6addrs
Steven> configured before distributing any prefixes and exclude ip6addr assigned
Steven> prefix parts from being reassigned again.
That's really what we need.
Steven> Regarding the other cases: It is possible to set ip6assign to something <64
Steven> so that a bigger prefix is assigned to a downstream-interface. With 6relayd
Steven> as DHCPv6-server this automatically makes anything but the first /64
Steven> available on the interface to downstream routers via
Steven> DHCPv6-PD (the first /64
Steven> is announced using RAs on the interface).
wow, that's really cool. I will actually use this then so that my main
router can then play ISP for my test router...
Steven> The technically better solution would be a mechanism where programs could
Steven> request a prefix via some RPC-mechanism from netifd. However
Steven> this would need
Steven> synchronization and callback-mechanism to inform the routing daemon when a
Steven> prefix is assigned / deassigned etc.
dare I suggest... dbus?
I know that network manager already sends out dbus messages about new
prefixes configured, and things like pidgin listen and reconnect when
they see a new prefix.
"everyone is doing it" (even the Automotive people)
] Never tell me the odds! | ipv6 mesh networks [
] Michael Richardson, Sandelman Software Works | network architect [
] mcr at sandelman.ca http://www.sandelman.ca/ | ruby on rails [
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Size: 307 bytes
Desc: not available
More information about the Cerowrt-devel