* Aidan Doyle <1114630054.426fe7a6d6e22@xxxxxxxxxxxxxxxxxxxx> 2005-04-27 12:27 > I'm working on a mobile mesh-networking router and I'd like to be able to modify > the hop-count assocated with a given route without having to do a delete > followed by add with the new hop-count. Aside from the overhead of the extra > system-call the removal/addition of the route could unnecessarily trigger > callbacks in other processes monitoring the route table. > > As far as I can tell this is not currently supported (I'm using kernel 2.6). > For instance if I use "ip route add" to add a route and then "ip route change" > with a new metric I get the err: "RTNETLINK answers: No such device" Actually it should be ENOENT if not this would be a bug. The metric/priority cannot be changed because we do not have separate fields for the fields to match and the new values so if you specify a metric the entry simply won't be found and the request fails with ENOENT because NLM_F_CREATE is not specified. This is a limitation of the current protocol and it might be a good idea to to change this, however it's non trivial and implies a modification to the rtnetlink protocol (no compatibility breakage though) and changes in the userspace code. - : send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
