From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick Caulfield Date: Tue, 30 Oct 2007 14:02:02 +0000 Subject: [Cluster-devel] Re: [PATCH] [DLM] Bind connections from known local address when using TCP In-Reply-To: <1193649745.1068.469.camel@quoit> References: <1193352544.20482.72.camel@ayanami.boston.devel.redhat.com> <1193649745.1068.469.camel@quoit> Message-ID: <4727395A.2080907@redhat.com> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Steven Whitehouse wrote: > Hi, > > On Thu, 2007-10-25 at 18:49 -0400, Lon Hohberger wrote: >> A common problem occurs when multiple IP addresses within the same >> subnet are assigned to the same NIC. If we make a connection attempt to >> another address on the same subnet as one of those addresses, the >> connection attempt will not necessarily be routed from the address we >> want. >> >> In the case of the DLM, the other nodes will quickly drop the connection >> attempt, causing problems. >> >> This patch makes the DLM bind to the local address it acquired from the >> cluster manager when using TCP prior to making a connection, obviating >> the need for administrators to "fix" their systems or use clever routing >> tricks. >> > > I'm happy to apply the patch, but I wonder why not just set the prefsrc > for the route? That will fix it for all applications not just the DLM. > Also if there are multiple NICs in the system with the same IP address > set assigned to them, then this solution may fail whereas the prefsrc > solution will continue to work as that allows specification of a device > too (amoung other things), I think it's appropriate to fix this in the DLM code. DLM doesn't work without it in this situation and there night (possibly!?) be applications that don't want prefsrc setting. -- Patrick