Description of problem:

I was trying to prevent iptables-save from loading kernel modules. I looked at "man iptables-save" which said:

SYNOPSIS
       iptables-save [-M modprobe] [-c] [-t table]

      -M modprobe_program
              Specify the path to the modprobe program. By default, iptables-save will
              inspect /proc/sys/kernel/modprobe to determine the executable’s path.

However:
# iptables-save -M /dev/null
iptables-save: invalid option -- 'M'
Unknown arguments found on commandline

while iptables-save --help or -h does not work, the binary does seem to show there must me a magic incantation for it, because strings on the binary shows:

Usage: %s [-b] [-c] [-v] [-t] [-h]
           [ --binary ]
           [ --counters ]
           [ --verbose ]
           [ --test ]
           [ --help ]
           [ --noflush ]
           [ --table=<TABLE> ]
          [ --modprobe=<command>]



Version-Release number of selected component (if applicable):
iptables-1.4.7-9.el6.x86_64

And indeed, --modprobe= seems to work as expected.

So there is a problem between the documented arguments and the actual arguments, possible induced by /sbin/iptables-save being an "/etc/alternative" link to /sbin/iptables-save-1.4.7

I'm not sure if the bug should be "fix the man page" or "fix the binary/link".

but if people were used to -M and now need --modprobe, perhaps iptables-save should allow for both now.