On Wed, Aug 12, 2015 at 4:52 AM, Alexander Duyck <alexander.du...@gmail.com> wrote: > On 08/10/2015 04:50 AM, Hannes Frederic Sowa wrote: >> >> Hello, >> >> Zang MingJie <zealot0...@gmail.com> writes: >> >>> Here comes several options: >>> >>> 1. reject local next hop w/ EINVAL >>> 2. delete route when local next hop removed >> >> Will also cause some people to complain. >> >>> 3. transition between RT_SCOPE_HOST amd RT_SCOPE_LINK >> >> I don't understand the scope transition. I know Alex mentioned it for >> the first time. Maybe he can explain? > > > If I am not mistaken part of the issue in terms of the behaviour being seen > is due to the fact that the nexthop scope is recorded only when the route is > added, and there is code in place in rt_set_nexthop which will only use the > gateway if the scope is RT_SCOPE_LINK. So what we would probably need to do > is go through and audit any routes on a given interface every time an > address is added or removed and if the nh_gw is equal to the address added > or removed would would need to transition between RT_SCOPE_LINK and > RT_SCOPE_HOST since the gateway is transitioning between the local system > and somewhere on the other side of the link. > > The problem is that this would still be a behaviour change and there may be > somebody that has heartburn about it.
That's why I'm going to introduce a sysconf entry, with the entry unset, keep compatibility; with the entry set, fix the bug. > >>> 4. document it >> >> I prefer that one :) > > > Yeah, me too. The fact is things have worked this way up until now and I > suspect the reason why this hasn't been reported until now is simply because > in many cases it works since routes are usually updated if you are moving > the gateway onto the local system. > > - Alex -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
