Creating Multiple Discard Interfaces

[=?unknown-8bit?Q?Jos=E9_Mar=EDa_Gonz=E1lez?=]

Hi, 

I'm trying to create several discard interfaces on 4.9-RELEASE, and I'm 
having 2 problems. This is what I see (comments started by //):

# ifconfig -a
de0: ...
lo0: ...
// these are my original interfaces

# kldload if_disc

# ifconfig -a
de0: ...
lo0: ...
ds0: flags=8008<LOOPBACK,MULTICAST> mtu 65532
// surprisingly enough, just loading the if_disc kernel module creates 
//	the ds0 interface for me. Well, I can live with that. 

# ifconfig ds0 create
ifconfig: SIOCIFCREATE: Invalid argument
# ifconfig disc0 create
ifconfig: SIOCIFCREATE: Invalid argument
// This makes sens, as the ds0 interface is already created

# ifconfig ds1 create
ifconfig: SIOCIFCREATE: Invalid argument
# ifconfig disc1 create
ifconfig: SIOCIFCREATE: Invalid argument
// 1st problem: How do I create ds1, ds2, etc.?


// Now I want to get rid of the if_disc module
# ifconfig ds0 down
# ifconfig ds0 destroy
ifconfig: SIOCIFDESTROY: Invalid argument
#ifconfig disc0 destroy 
ifconfig: interface disc0 does not exist
# kldunload -v -i 4
Unloading if_disc.ko, id=4
kldunload: can't unload file: Invalid argument
// 2nd problem: How do I get rid of the if_disc module?


Thanks for any help you can provide. 
-Chema