Hi Fernando,
>________________________________ > From: Fernando Gont <fg...@si6networks.com> >To: Ray Hunter <v6...@globis.net> >Cc: "6man-cha...@tools.ietf.org" <6man-cha...@tools.ietf.org>; Brian Haberman ><br...@innovationslab.net>; "6...@ietf.org" <6...@ietf.org>; RJ Atkinson ><rja.li...@gmail.com>; t.petch <daedu...@btconnect.com> >Sent: Friday, 26 April 2013 2:47 AM >Subject: Re: LC comments on stable-privacy-addresses: Interface Index vs. name > > >Hi, Ray, > >On 04/25/2013 11:21 AM, Ray Hunter wrote: >> Since both "Interface_Index" and "Interface name" are anyway both >> implementation dependent, why would you need to precisely standardise >> the exact meaning, or the exact source of the information? AFAICS this >> wouldn't significantly affect inter-op, or protocol operation. > >Their implementation (e.g. namespace) are implementation-dependent. >Their properties may not. > >I don't care about the source of information as long as it meets the >goal. Ideally, the I-D: > >* Should be constant across system bootstrap sequences >* Should be different for each network interface >* Should not change when the NIC is replaced > I think listing those desired properties would be useful, and then describing examples of actual interface identifiers that would qualify if available e.g., persistent ifindex values or persistent interface names. One thing that has occurred to me is the interface identifier stability you're looking for would probably be provided by deriving the interface ID from the system connector that is used to attach the network interface to the system e.g. the PCI slot information. A swap of a failed interface, despite changing the MAC address, will retain the same interface ID. This gets a bit interesting when thinking about the USB NIC situation. Plugging the USB NIC into different USB slots would change the interface ID if the slot is used to assign it a persistent interface ID. OTOH, the MAC address and other properties of the USB NIC (such as USB serial number if it has one) would be constant, so they could be used to create a persistent interface ID for your purposes, despite the different USB slot used to attach it to the system. Perhaps that means different buses and/or connectors would need different policies on interface ID assignment, and that could be mentioned in your Draft. As another example of a convention, it seems that Fedora has adopted a convention of naming wired ethernet interfaces based on whether they're attached to the motherboard (e.g, em0) or a PCI slot / port and then virtual function if it has one (e.g. p4p1), so they're persistent across boots or replacement. Yet they don't apply that to PCI attached wifi interfaces, which are still called wlanX. You might also want to briefly cover persistent interface IDs for virtual interfaces e.g, bridge virtual interfaces. Their only constant identifier may be their name - under Linux for example, they seem to use the lowest numeric MAC address of the member interfaces, which can change if a new interface is added or the lowest MAC address interface is removed. <snip> Regards, Mark. -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
