Chris Friesen wrote: > Hi all, > > I've got a few questions about the current implementation of SCTP. > Suppose I have two network nodes, each of which has two IP addresses. > Theoretically this results in four possible paths between the two nodes. Theoretically, but often not in practice. > > If the network device corresponding to the primary IP address goes down > on the remote node, will the current implementation properly switch over > to use the "most divergent source-destination pair" as suggested in the > RFC? I assume this would mean switching to the other IP address on both > nodes? It sort of depends on how the addresses are configured. Assuming a typical multihomed scenario where each address is in its own subnet, then the answer is yes. Ex: node A (addrs: 1.2.3.4, 2.3.4.5) <---------> Node B (addrs: 1.2.3.5, 2.3.4.6) In this case, assuming 1.2.3.0/24 was primary, the path with switch to 2.3.4.5 <--> 2.3.4.5. It really is a function of the routing looking by the kernel. > > Same question, but with the device corresponding to the primary IP > address going down on the local node. Once the appropriate time-outs happen, it should switch the same as above. > > If a chunk times out, will the current implementation retransmit it via > the "most divergent source-destination pair" as suggested in the RFC? Most of the time. We simply try to pick a different destination address to send to, and let the kernel pick a source. As long as the source picked by the kernel is within our bound set, we'll use it. We don't check for 'mostly divergent pair'. -vlad > > Thanks, > > Chris > -- > 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
