IPv6 Core (cont'ed): Policy Routing vs Address Selection

• A policy may depend on source address.

• Source address selection is decided after routing decision (especially interface decision), if upper layer has not specified one.

• FIB_RULE_FIND_SADDR flag

• • Ignore the source address in the rule and find a best route.
  • Decide source address and check if it is okay for the rule used.