[libvirt] [PATCH v4 07/17] Domain network devices can now have a <gateway> element

[Daniel P. Berrange]

On Tue, Dec 02, 2014 at 04:39:02PM +0300, Dmitry Guryanov wrote:
> On Thursday 13 November 2014 10:33:06 Cédric Bosdonnat wrote:
> > Network interfaces devices and host devices with net capabilities can
> > now have an IPv4 and/or an IPv6 address configured.
> 
> I would rename "gateway" to "route", so it will mean an entry in a routing 
> table. Because there will certainly be people, who would want to configure 
> routing table more precisely than just setting default gateway.
> 
> Something like
> <route to="10.10.0.0/16" via="10.3.0.1">
> 
> Routing table is separated from devices configuration in the kernel, and some 
> route types don't have output device, for example blackhole. So maybe it's 
> better to move route from interface definition to outer scope and add "dev" 
> parameter.

Hmm, if you have multiple IP addresses per device, you I guess you can
also have multiple default routes - one for each subnet range really

eg

      <ip address='192.168.122.5' prefix='24'/>
      <ip address='10.0.2.4' prefix='24'/>
      <gateway ipv4='192.168.122.1'/>
      <gateway ipv4='192.0.2.1'/>

So I at leaast agree that we need more than just a single <gateway> per
address type. I do like the routs associated with the <interface>
though. I'd be inclined to have

  <route family="ipv4|ipv6" address="10.0.0.0" prefix="16" via="10.0.0.1"/>

under the <interface>. The address + prefix attrs could be optional if
there is only a single <ip> for a given family. eg in the simple case
we could get this for a "default route"

  <route family="ipv4|ipv6" via="10.0.0.1"/>

If we ever find a real world need to have routes not associated with a
device, we can address that then.


Regards,
Daniel
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