On Fri, Jun 12, 2015 at 05:04:48PM +0200, Bjoern Franke wrote:

Hi Linus,

...

There's a hash_max value for the bridge (/sys/class/net/<br>/bridge/hash_max). By default it's rather small, just 512 entries / multicast listeners, so it's expected that with 500 nodes the bridge multicast snooping will shut down.

Thanks for your reply, I increased the value now to 4096 on the gateways.

...

Nevertheless, even if the bridge deactivates its multicast snooping that shouldn't cause trouble for ICMPv6.

Which firmware are you using, do you see ICMPv6 packets entering bat0 on the gateway and leaving bat0 on the router?

We are running gluon 2014.4 on the routers.

Okay. In Gluon both the batman-adv multicast optimizations and bridge multicast snooping are deactivated by default. So I think it's probably an issue with the bridge on your gateway. Does deactivating the batman-adv and bridge multicast stuff make a difference?

Which kernel version and Linux distribution are you using on the gateway?

I see solicitations and advertisements on the gateway: 16:59:54.567582 IP6 fd74:fdaa:9dc4:0:fa1a:67ff:feeb:c77e > ff02::1:ff40:1: ICMP6, neighbor solicitation, who has fd74:fdaa:9dc4::40:1, length 32 16:59:54.567661 IP6 fd74:fdaa:9dc4::40:1 > fd74:fdaa:9dc4:0:fa1a:67ff:feeb:c77e: ICMP6, neighbor advertisement, tgt is fd74:fdaa:9dc4::40:1, length 32

Measured on bat0 or on the bridge on top?

Unfortunately it's not possible to access the router at the moment to have look what's leaving on bat0 there.

Regards Björn

Cheers, Linus

PS: Please keep the mailinglists.