Re: [PATCH 1/1] Network: support default route metric per interface

On 9/28/20 6:54 PM, Qingtao Cao wrote:

Hi David,

I understand I can use the "metric" parameter along with the "ip addr
add/change" and "ip route add/change" commands to make use of the
IFA_RT_PRIORITY attribute to explicitly specify the metric for routes
created directly or associated with added addresses, and the network
manager should do this.

But what if userspace can bypass the network manager? or forgetting to
apply the "metric" parameter for example directly on the CLI?

use a sticky note? :-)

Then the kernel will fall back on the same default metric (such as 0 for
ipv4 and IP6_RT_PRIO_ADDRCONF(256) or USER(1024) for ipv6) for ALL
interfaces. So I think the def_rt_metric patchset can be regarded as
having the kernel providing a mechanism for the uerspace to specify
DIFFERENT default routes per interface, which does not necessarily
indulge the userspace network manager skipping over specifying the metic
explicitly

What do you think?

I think it is a userspace, configuration management problem.