Subject: Re: [RFC PATCH 00/29] net: VRF support

From: David Ahern <[email-masked]>
Date: Thu, 05 Feb 2015 18:32:22 -0700

On 2/5/15 6:44 AM, Nicolas Dichtel wrote:
> Le 05/02/2015 02:34, David Ahern a écrit :
> [snip]
>> This is accomplished by enhancing the current namespace checks to a
>> broader network context that is both a namepsace and a VRF id. The VRF
>> id is a tag applied to relevant structures, an integer between 1 and 4095
>> which allows for 4095 VRFs (could have 0 be the default VRF and then the
>> range is 0-4095 = 4096s VRFs). (The limitation is arguably artificial. It
>> is based on the genid scheme for versioning networking data which is a
>> 32-bit integer. The VRF id is the lower 12 bits of the genid's.)
> Would it be possible to avoid this artificial limit?
> There could be scenarii with more than 4096 vrf.

As I recall the genid was the only reason to put a limit on it. I know 
of one product with a higher limit (16k I believe), but I figured this 
was a reasonable start point for the discussion.

>
> Do you plan to have a way to dump or monitor VRF via netlink?

What do you mean? There is no creation / deletion event. Are you 
referring to monitoring device changes -- device moved from one network 
context (namespace, vrf) to another?

The VRF id can be added as an attribute to all relevant netlink 
notifications.