On Wed, Dec 03, 2014 at 05:57:18PM +0100, Boiteux Frederic wrote: > Hi Vlad, > > >> When I start SCTP messages exchanges, the hosts are using the first > >> address, which is working, and messages are correctly transmitted. On > >> the peer of the failing-IP host, I get notifications that this IP > >> address is UNREACHABLE, it's correct. In fact, I get one notification > >> each 100ms, but this can probably be setup. > > >No, this was an issue that was recently addressed. See >https://git.kernel.org/cgit/linux/kernel/git/davem/net.git/commit/?id=061079ac0b9be7a578dcd09f7865c2c0d6ac894a > > Right. But it's not a big problem to ignore them... > > >> The problem is that after some time of message exchanges, about 20 > >> seconds, the hosts get a LOST notification for the association and no > >> message can't be sent anymore until a new association is built. > > >Which host gets the LOST notification? > > It's the host receiving UNREACHABLE notifications (not the host having a failed IP, but its peer). It's why I wondered if association breakage and these notifications was related. > It sounds to me like you just can't include multihoming with the address you're referring to. E.g.: Host A has ip addresses 1 and 2 Host B has ip addresses 3 and 4 Host A ip 2 isn't routeable Regardless of Host A's unrouteable ip address 2, its getting included in the INIT chunk when you establish a connection with Host B, and Host B is then trying to reach Host A by ip address 2, which your network is rejecting due to its unrouteable nature. The only thing I'm aware of to do here is not inlucde that address, but using the connectx call and not including the unrouteable address. Neil > ... > > >> is the LOST related to these UNREACHABLE notifications, or should I > >> look for other cause ? > > >It might be, or it might be related to some transport selection code that has seen some good fixes. > > It would be good if you could try this on a recent kernel to see if you still see the issue. > > I tested my application on virtual systems having the same kernel/system, and tried to do the same configuration, but didn't reproduce the problem. > > As it's difficult/impossible to upgrade the kernel (without modifying the system, and I can't do that), do you think backporting sctp kernel module is a way to test this ? > > Anyway, given the 'UNREACHABLE' notifications is a wrong suspect, I'll try to do some network packets' capture to try to understand what is going on... > > Many thanks, > Fred. > > -- > To unsubscribe from this list: send the line "unsubscribe linux-sctp" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
