"bug" with ifconfig ... ?

[Marc G. Fournier]

I just made one of my 4.x remote servers inaccessible and just tested it on my 
5.x laptop, and it does the same thing ... not sure if this is considered a 
'desirable' effect, or a but ... but ... 'ifconfig <device> -alias' will wipe 
out all IPs on the device:

mobile# ifconfig -a
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
         inet 127.0.0.1 netmask 0xff000000 rl0: 
flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
         options=8<VLAN_MTU>
         inet 192.168.0.5 netmask 0xffffff00 broadcast 192.168.0.255
         ether 00:0d:88:22:78:e4
         media: Ethernet 10baseT/UTP
         status: active
mobile# ifconfig rl0 -alias
mobile# ifconfig -a
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
         inet 127.0.0.1 netmask 0xff000000 rl0: 
flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
         options=8<VLAN_MTU>
         ether 00:0d:88:22:78:e4
         media: Ethernet 10baseT/UTP
         status: active


I was running a script that happened to pick up a 'zero length' IP (and I 
hadn't properly tested for it), so erased all the IPs configured on that 
device, instead of generating an error ...

Checking the man page, if this *is* desired effect, a bit of a warning might be 
in order:

"     -alias  Remove the network address specified.  This would be used if
               you incorrectly specified an alias, or it was no longer needed.
               If you have incorrectly set an NS address having the side
               effect of specifying the host portion, removing all NS
               addresses will allow you to respecify the host portion."

"Remove the network address specified.", to me, means that if one isn't 
specified, nothing should/would happen :(

----
Marc G. Fournier           Hub.Org Networking Services (http://www.hub.org)
Email: scrappy at hub.org           Yahoo!: yscrappy              ICQ: 7615664