From mboxrd@z Thu Jan 1 00:00:00 1970 From: Or Gerlitz Subject: Re: issues with the rdma-cm server side mapping of IP to GID Date: Sun, 2 Mar 2014 10:51:19 +0200 Message-ID: <5312F107.2000404@mellanox.com> References: <530C51EF.2000509@mellanox.com> <1828884A29C6694DAF28B7E6B8A8237388D1F0BD@ORSMSX109.amr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1828884A29C6694DAF28B7E6B8A8237388D1F0BD-P5GAC/sN6hkd3b2yrw5b5LfspsVTdybXVpNB7YpNyf8@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Hefty, Sean" Cc: "linux-rdma (linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org)" , Yan Burman List-Id: linux-rdma@vger.kernel.org On 02/03/2014 01:50, Hefty, Sean wrote: >> Such situation can happen in the following cases: >> >> 1. net.ipv4.conf.default.arp_ignore equals 0 (the default) >> 2. server side bonding/teaming fail-over when the Gratitous ARP sent was >> lost >> 3. re-order of ibM net-devices mapping to HCA PCI devices after server >> boot/crash >> 4. etc more >> >> Basically, when the rdma-cm observes difference between the destination GID as present in the IB path within the CM REQ to the one resolved locally, we should at least print a warning. Perhaps, we should reject the connection request? (in that case, I wasn't sure what would be the appropriate reject reason), any more ideas? > I'm not sure that this results in a single error case. Sorry... I'm not sure to follow, can you elaborate a bit more? > Can the kernel rdma_cm check for net.ipv4.default.arp_ignore on startup and at least print a warning if that is wrong? I am not sure, and anyway, please note that I brought at least two more use cases where the problem happens - following server side bonding fail-over - following server side reboot after which the PCI ordering changes between two HCAs and hence ibM devices change their PCI association Or. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html