Source/Policy Based Routing

Onload User Guide (UG1586)

Document ID
Release Date
1.2 English

OpenOnload 201710 / EnterpriseOnload 6.0

The Onload 201710 and EnterpriseOnload 6.0 releases include support for source based policy routing for unicast and multicast packets. The following are supported:

  • source ip address
  • destination ip address
  • outgoing interface (SO_BINDTODEVICE)
  • TOS (Type of Service)

Policy rules based on other criteria are not supported and will be ignored by Onload.

Earlier Onload Versions

Earlier Onload versions do not support source based or policy based routing. Whereas the Linux kernel will select a route and interface based on routing metrics, Onload will select any of the valid routes and Onload interfaces to a destination that are available.

The EF_TCP_LISTEN_REPLIES_BACK environment variable provides a pseudo source-based routing solution. This option forces a reply to an incoming SYN to ignore routes and reply to the originating network interface.

Enabling this option will allow new TCP connections to be setup, but does not guarantee that all replies from an Onloaded application will go via the receiving interface - and some re-ordering of the routing table might be needed to guarantee this OR an explicit route (to go via the receiving interface) should be added to the routing table.