Re: Proposal: enable stateless persistant network interface names
On Fri, May 08, 2015 at 10:50:30AM -0700, Josh Triplett wrote:
> Karsten Merker wrote:
> > while this probably works resonably well for (semi-)fixed devices
> > like onboard-NICs and PCI/PCIe cards, it results in a completely
> > unsuitable behaviour with pluggable devices such as USB network
> > adapters. When using ifnames, the interface name depends on the
> > USB port into which the device is currently plugged and the
> > interface name changes when one uses a USB hub or plugs the
> > device into another host port. This would mean that a user would
> > always have to plug his USB network device into the same port
> > that was used during initial setup to keep it working, and
> > one-off use of a USB hub would require changing the network
> > configuration. Despite the problems of the MAC-based system
> > that we use currently, the ifnames method appears way worse
> > to me than what we have now.
>
> That would only be a problem if you're using ifupdown and its hardcoded
> network interface names. Other network software handles dynamic names.
How is for example iptables supposed to handle changing interface
names? IPtables rules often specify a specific incoming or
outgoing interface, so the interface name must be known at the
ruleset load time. This would mean that with the ifnames
mechanism and its port-based interface naming, an iptables
ruleset on a laptop with a USB network adapter would only work if
the adapter is either always plugged into the same port or the
user changes the ruleset every time he uses another USB port.
> Without this, you can't reliably use a system with *two* USB network
> devices, because they won't consistently come up with the same names.
> Or, for that matter, a system with a built-in network interface and a
> USB network interface.
The current default MAC-based mechanism handles exactly this case
very well on a number of systems for me (one built-in network
interface and one or two USB network adapters). Every adapter
always gets the same interface name, regardless of the bringup
order.
Regards,
Karsten
--
Gem. Par. 28 Abs. 4 Bundesdatenschutzgesetz widerspreche ich der Nutzung
sowie der Weitergabe meiner personenbezogenen Daten für Zwecke der
Werbung sowie der Markt- oder Meinungsforschung.
Reply to: