Re: [Questions] Some issues about IPv4/IPv6 nexthop route

David Ahern
2023-08-28T15:06:26Z

On 8/28/23 1:53 AM, Hangbin Liu wrote:
> On Thu, Jul 27, 2023 at 05:45:02PM +0300, Ido Schimmel wrote:
>>> Since the route are not merged, the nexthop weight is not shown, which
>>> make them look like the same for users. For IPv4, the scope is also
>>> not shown, which look like the same for users.
>>
>> The routes are the same, but separate. They do not form a multipath
>> route. Weight is meaningless for a non-multipath route.
>>
>>> But there are 2 issues here:
>>> 1. the *type* and *protocol* field are actally ignored
>>> 2. when do `ip monitor route`, the info dumpped in fib6_add_rt2node()
>>> use the config info from user space. When means `ip monitor` show the
>>> incorrect type and protocol
>>>
>>> So my questions are, should we show weight/scope for IPv4?
>
> Here is the first one. As the weight/scope are not shown, the two separate
> routes would looks exactly the same for end user, which makes user confused.

Asked and answered many times above: Weight has no meaning on single
path routes; it is not even tracked if I recall correctly.

> So why not just show the weight/scope, or forbid user to add a non-multipath
> route with weight/scope?

That is a change to a uAPI we can not do at this point.

>
>>> How to deal the type/proto info missing for IPv6?
>
> What we should do for this bug? The type/proto info are ignored when
> merge the IPv6 nexthop entries.

I need more information; this thread has gone on for a long time now.