Re: too long mac address for --mac-source netfilter option

From: Mr. James W. Laferriere (
Date: Fri Feb 16 2001 - 21:09:26 EST

        Hello Jack & All , Might this be an atm interface ?
        If it is not then am I to assume that an atm interface
        with its erroneous mac-address is going to have the same
        difficulties . That is of course as soon as the atm interface
        actually put a valid ESI/mac-address into the interface table .
                Tia , JimL

On Fri, 16 Feb 2001, Jack Bowling wrote:
>> I am trying to use the --mac-source option in the netfilter code to
>better refine access to my linux box. However, I have run up against
>something. The router through which my private subnet work box passes
>sends a 14-group "invalid" mac address, presumably as an attempt to
>conceal the real hextile mac address. However, the code for the
>--mac-source netfilter option is looking for a valid hextile mac address
>and complains loudly as such (numerals converted to x's):
> iptables v1.1.1: Bad mac address `xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx'
> to the respective iptable line:
>> $IPT -A INPUT -p tcp -s -d $NET -m mac --mac-source
>xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx --dport 5900:5901 -j ACCEPT
>> The idea here is to allow VNC access to my home box with the access
>filtered by both IP and mac address.
>> Is there a resolution to this other than a rewrite and recompile of the
>relevant sections of the iptable code? Or am I stuck? I know this option
>is tagged by Rusty as experimental still so I would assume that the code
>is open for feedback ;) The question could be rephrased as: is there any
>chance of allowing "invalid" mac addresses to be recognized by the
>--mac-source option of the netfilter code? Running Redhat v7/kernel

       | James W. Laferriere | System Techniques | Give me VMS |
       | Network Engineer | 25416 22nd So | Give me Linux |
       | | DesMoines WA 98198 | only on AXP |

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This archive was generated by hypermail 2b29 : Fri Feb 23 2001 - 21:00:14 EST