Hi, I have a question regarding equal-cost multipath routing. Here is what I want to do: couple two 16 MBit DSL lines, as I'd need the speed of both combined. Here on my side, a FTP server will run, and on the other side, a FTP client, doing up to 20 connections in parallel. Between the ftp client host, and the FTP server, I wanted to setup two OpenVPN tunnels.
So I read the FAQ regarding the topic, and the mentioned RFC 2992. In the RFC I read: One method for determining which next-hop to use when routing with ECMP can be called hash-threshold. The router first selects a key by performing a hash (e.g., CRC16) over the packet header fields that identify a flow. and then in the route(8) manual page: When multiple routes exist for a destination, one route is selected based on the source address of the packet. The sysctl(8) vari- ables net.inet.ip.multipath and net.inet6.ip6.multipath are used to con- trol multipath routing. If set to 1, multiple routes with the same pri- ority are used equally; if set to 0, the first route selected will be used for subsequent packets to that destination regardless of source. So the question I now have is, in my scenario, I only have one source and one destination for all the connections. When I understand the manual page of route(8) correctly, then everything will take the same tunnel. Either with activated multipath, because the source IP address will be the same all the time, and with disabled multipath, it will take the first route that can be found in the routing table. kind regards Sebastian
