[Cerowrt-devel] Current state of ipv6 in openwrt barrier breaker

Steven Barth cyrus at openwrt.org
Wed Dec 12 04:47:44 EST 2012

Hi Ole,

> you could use hierarchical PD, just that it doesn't work well with:
>   - networks with loops
>   - multi-homed networks
> and it is quite wasteful with regards to subnet space.
> ND proxy fails in any topology with a loop.
Yes but I expect loops not to happen in practice or people that build 
loops to know how to take care of them.

Nevertheless taking into account the issues I mention below hierarchical 
PD still sounds to me like a better thing in SOHO environments regarding 
interoperability with other devices in that environment however as I 
still need the NDP-Proxying fallback in case the upstream router (be it 
a SOHO-router) doesn't support further distribution of the ISP-Prefix.

> we do have an implementation on github that implements
> http://datatracker.ietf.org/doc/draft-arkko-homenet-prefix-assignment/
> that supports prefix assignment with an arbitrary topology in the network. why not use that?
 From a technical point of view I like your approach and using OSPF.

However the stuff is >1 MB in size including all of its dependencies and 
includes some strange dependencies like libreadline?, some otherwise 
unrelated Lua extensions and so on.

Sorry, that is not an option for the majority of OpenWrt users, just for 
having a more versatile Prefix Delegation feature which will only be (?) 
interoperable with a small amount of routers.

We could integrate it for more powerful routers though (and I wouldn't 
object) but I don't see any hope to get it to mainstream before we can 
get it down to a few 100 KB (including dependencies).
Also at least I don't have any time or resources to take care of either 
of that in the near future.

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