On Sun, May 01, 2011 at 12:15:51AM +0200, Benjamin Kiessling wrote: > Hi, > > I've been trying to get OpenOSPFd working on OpenBSD 4.8 using an GRE over > IPsec approach. The GRE tunnel is working for unicast IPv4 packets. I've seen > that there are reject routes for 224.0.0.0/4 in the default configuration and > set multicast_host to yes which adds the route to the default interface (vr1 > in my case). Adding this route to the gre0 device either manually or with the > multicast_host key fails. As I just installed OpenBSD a few days ago I'm > clueless about how to proceed. > > What is the proper way to enable multicast on gre devices? Additionally, if I > understand the configuration correctly multicast is only supported on one > device simultaneously (can't really believe that). How would I then use OSPF > on one interface and an IPv6 router advertisement demon on another? > > I apologize if these questions seem rather basic and/or if solutions are > provided in the documentation (coming from the Linux world I have to say > OpenBSDs man pages are even more marvellous than sliced bread). >
ospfd does not need any of the multicast options. ospfd uses the IP_MULTICAST_IF socket option and bypasses the routing table lookup by doing so. rtadvd and many other daemons do it in a similar way. The multicast_host option is only needed for applications that do not use the special multicast setsockopt()s. Now this is not entierly true at the moment because UDP sockets behave a bit differently but this is something I hope to change soon. In the end ospfd, ripd, rtadvd and many other daemons run out of the box and if not the manpage would tell you which settings need to be changed. E.g. gre(4) needs the net.inet.gre.allow sysctl to be set to 1. -- :wq Claudio
