On 8/1/19 10:13 PM, Hangbin Liu wrote: > On Thu, Aug 01, 2019 at 01:51:25PM -0600, David Ahern wrote: >> On 8/1/19 2:29 AM, Hangbin Liu wrote: >>> Jianlin reported a bug that for IPv4, ip route get from src_addr would fail >>> if src_addr is not an address on local system. >>> >>> \# ip route get 1.1.1.1 from 2.2.2.2 >>> RTNETLINK answers: Invalid argument >> >> so this is a forwarding lookup in which case iif should be set. Based on > > with out setting iif in userspace, the kernel set iif to lo by default.
right, it presumes locally generated traffic. > >> the above 'route get' inet_rtm_getroute is doing a lookup as if it is >> locally generated traffic. > > yeah... but what about the IPv6 part. That cause a different behavior in > userspace. just one of many, many annoying differences between v4 and v6. We could try to catalog it.
