[linux-sparc-users] multiple MAC addresses on sparc Linux LDOM?

[Richard L. Hamilton]

> On Sep 21, 2016, at 08:58, Alexandre Chartre <alexandre.chartre at oracle.com> wrote:
> 
> 
> On 09/21/2016 01:44 PM, Richard L. Hamilton wrote:
>> Since 3.something of LDOMs, one could assign multiple MAC addresses
>> to an LDOM, although it was only said to be supported for Solaris 11
>> guests, not Solaris 10.
> 
> Right, LDoms has support for alternate MAC addresses (ldm set-vnet alt-mac-addrs=...),
> to have multiple MAC addresses on the same vnet.
> 
>> Can SPARC Linux make use of them?  I'd like to run an emulator using
>> tun/tap for bridged networking within a Linux LDOM (because it will
>> probably be less of a pain to compile for that than for Solaris), and
>> that's the only Linux I've got that's running 24/7 anyway, so if I
>> want to leave the emulator running, that would be the best
>> place...but it would need an extra MAC address for that.
> 
> No, alternate MAC addresses is not supported by the current Linux sunvnet
> driver.

> Maybe you can use a second vnet connected to the same vswitch. That way
> your domain will have two MAC addresses on the same network (same vswitch)
> but on two different vnet interface.
> 
> alex.
> 


Thanks! - a practical suggestion, probably doable once I figure out the necessary ldm commands, subject to one possible complication: is there some state (e.g. visible but marked down) in which I can send raw Ethernet packets out such an additional interface while having the domain's Linux OS otherwise ignore the interface?  Typical emulators use TUN/TAP, either with TUN (IP injection, which takes playing games with routes and proxy ARP, and may not play well with firewalls, routers, or NAT), or with TAP (raw Ethernet packets with an alternative MAC address, essentially bridging).  The latter if possible works far better. :-)

Also - if it would not be too difficult, I'd sure like to see multiple MAC address support added to Linux sunvnet driver one day. :-)   There are probably uses other than the specific one I have in mind, even if I'd be hard-pressed to think of them at the moment.