On Fri, Apr 29, 2016 at 04:58:04PM +0200, smlng wrote: > Hi Alex, > hi all, > > over the last days I did some more extensive tests and enabled/added some debug output in RIOT, and I got close to the root cause of the problem. > > TL;DR: > - Linux does not set the router flag in its NAs > - but it should when `radvd` is running (or `radvd` should enable it). > - RIOT behaves correctly, according to RFC-4861 7.2.4. > > ---- > > Now the slightly longer version; I quickly recap my setup: > > - a RasPi with OpenLabs transceiver, and `radvd` (linux-wpan version from github) > - Atmel samr21-xpro running RIOT with `gnrc_networking` example (2016.04-branch) > - `radvd` announces a ULA-prefix (though ULA doesn't matter, could global as well) > > I observed the following behavior: > > - RIOT send RS on boot, `radvd` on RasPi replies with RA (incl. PIO, ABRO, SLLAO) > - RIOT parse RA, generates IP from prefix, adds NCE for router with router flag set > - RIOT send NS for RasPi/routers link-local address -> RasPi replies with NA > - RIOT parses NA, but router flag not set -> unset router flag in NCE of router > - hence no more router in cache -> no ping or data transfer via non-link-local (e.g. ULA) IPs > > so my question @alex and @linux-wpan: can I manually set/enable the routers flag for NAs in Linux Kernel? Or somehow _convince_ `radvd` to do so on startup? Routers are indicated by the "forwarding" setting. radvd silent warns about that if this isn't set for interfaces with RA advert is on, so far I know you need to increase the debug level for that. I simple set: echo 1 > /proc/sys/net/ipv6/conf/all/forwarding this will set forwarding for all interfaces. Some code explaining: See http://lxr.free-electrons.com/source/net/ipv6/ndisc.c#L838 this is at function when NS is received, the routeri flag will be set when forwarding is enabled. Maybe this solves all your current issues. :-) > I'm running latest Raspbian with Kernel 'Linux raspberrypi 4.1.19+' and wpan-tools from github on the RasPi. > I would better use bluetooth-next, if possible. With all recent patches you could also try to use 6CO in radvd. btw: the radvd wants to accept my patches for 6lowpan 6CO stuff, but basic 6LoWPAN-ND (first short address support for NA/NS) will be added and short-address handling will not work with RIOT, but that's another issue... - Alex -- To unsubscribe from this list: send the line "unsubscribe linux-wpan" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
