On Sun, 17 Oct 2010, Nikolay Denev wrote:

Hello,

While playing with vnet jails I've discovered the following oddity, which 
probably is not what's expected to happen :

...
And that's what ifconfig shows after this :

   [16:52]r...@nas:/home/ndenev# ifconfig
   <... snip lo0 and physical interface ...>
   epair0a: flags=8842<BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
            ether 02:8c:53:00:03:0a
   epair1a: flags=8842<BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
           ether 02:b6:49:00:05:0a
   eth0: flags=8842<BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
            ether 02:8c:53:00:04:0b
            ether 02:b6:49:00:06:0b

Instead of two interfaces, I'm seeing one with to lladdrs, because of the 
interface names being the same.

Then I'm trying to destroy them :

   [16:52]r...@nas:/home/ndenev# ifconfig eth0 destroy
   [16:53]r...@nas:/home/ndenev# ifconfig
   <... snip lo0 and physical interface ...>
   epair1a: flags=8842<BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
            ether 02:b6:49:00:05:0a
   eth0: flags=8842<BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
            ether 02:b6:49:00:06:0b
   [16:53]r...@nas:/home/ndenev# ifconfig eth0 destroy


So in this case there may be not a clean way to address one of the interfaces 
specifically (i.e. destroy only the second one)?

I've not investigated further, but I'm thinking probably this is just a "bug" 
in ifconfig interpreting/parsing the information from the kernel.
Maybe a solution is to extend ifconfig to be able print the interface list 
along with the ifIndex values and also manage the interfaces by index?
Auto renaming also is also probably a possible solution (i.e. eth0_1 , eth0_2 ) 
as these are interfaces coming from destroyed vnet's and are not likely to be 
in use. (but still sounds scary :) )

It's actually a bug in sys/net/if.c:if_vmove* we know about and that's
on the todo list.

I am not sure when the behaviour of ifconfig changed as previousy it
would only show you one of the two interfaces with the single ether
address.  ifconfig -l however had shown eth0 twice.  Neither is really
what one would expect thus needs changing.

/bz

PS: freebsd-virtualization@ is the best list to report "VIMAGE" or
"vnet" related problems.

--
Bjoern A. Zeeb                              Welcome a new stage of life.
_______________________________________________
freebsd-net@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-net
To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"

Reply via email to