On Fri, 27 Jan 2006, Alexander Hall wrote:
> Hi!
>
> I just noticed (the hard way) a strange behaviour of ifconfig. In short, if I
> supply a netmask when removing an alias with ``-alias <address>'', it is not,
> as one would expect, ignored, but rather used as the netmask for the primary
> address of the interface.
>
> While it would not be necessary to supply the netmask when removing an alias,
> I cannot see that this behaviour would be expected. I would rather expect an
> error or that the netmask was ignored.
>
> Or am I totally wrong?
alias/-alias is a _parameter_ and should come after the address.
It would be better if ifconfig would be more strict, but its argument
parsing code is a nightmare....
-Otto
>
> Example follows:
>
> $ ifconfig xl0
> xl0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
> lladdr 00:06:5b:36:f8:e1
> groups: egress
> media: Ethernet autoselect (100baseTX full-duplex)
> status: active
> inet6 fe80::206:5bff:fe36:f8e1%xl0 prefixlen 64 scopeid 0x1
> inet 192.168.2.130 netmask 0xffffff00 broadcast 192.168.2.255
> $ sudo ifconfig xl0 inet alias 192.168.2.140 netmask 255.255.255.255
> $ ifconfig xl0
> xl0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
> lladdr 00:06:5b:36:f8:e1
> groups: egress
> media: Ethernet autoselect (100baseTX full-duplex)
> status: active
> inet6 fe80::206:5bff:fe36:f8e1%xl0 prefixlen 64 scopeid 0x1
> inet 192.168.2.130 netmask 0xffffff00 broadcast 192.168.2.255
> inet 192.168.2.140 netmask 0xffffffff broadcast 192.168.2.140
> $ sudo ifconfig xl0 inet -alias 192.168.2.140 netmask 255.255.255.255
> ifconfig: SIOCAIFADDR: File exists
> $ ifconfig xl0
> xl0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
> lladdr 00:06:5b:36:f8:e1
> groups: egress
> media: Ethernet autoselect (100baseTX full-duplex)
> status: active
> inet6 fe80::206:5bff:fe36:f8e1%xl0 prefixlen 64 scopeid 0x1
> inet 192.168.2.130 netmask 0xffffffff broadcast 192.168.2.130
> ^^^^^^^^^^
> madness
>
> /Alexander
