Re: Should linux send netlink message as it is deleting that routing entry?

[zhuyj <zyjzyj2000@gmail.com>]

On 04/12/2014 02:30 AM, Stephen Hemminger wrote:
> On Fri, 11 Apr 2014 17:15:48 +0800
> zhuyj <zyjzyj2000@gmail.com> wrote:
>
>>> With ubuntu 12.04, I run the following to reproduce this defect.
>>>
>>> 1) Configure an interface
>>> ifconfig eth1 150.0.0.1/24 up
>>>
>>> 2) Add routing entry via that interface address
>>> route add -net 200.0.0.0/24 gw 150.0.0.1
>>>
>>> 3) Change the ip address on that interface as shown below.
>>> ifconfig eth1 151.0.0.1/24 up
>>>
>>> 4) Check netlink messages with "ip monitor all". There is no route
>>> delete netlink message.
>>>
> With IPv4 there are several cases where there is a non-notified
> implicit route withdrawal. This is not something that can be fixed.
> There are two issues:
>   1. with large backbone size route tables (ie 1M routes), the number
>      of notification messages becomes a bottleneck and would be unreliable
>   2. the existing routing daemons (quagga, bird, etc) all understand/expect
>      the existing semantics
>
Hi,

Thanks a lot.

Best Regards!
Zhu Yanjun