Re: clone packet with new destination address

[Stephen Clark <sclark46@earthlink.net>]

On 10/22/2010 09:36 AM, Changli Gao wrote:
> On Fri, Oct 22, 2010 at 9:24 PM, Changli Gao<xiaosuo@gmail.com>  wrote:
>    
>> On Fri, Oct 22, 2010 at 8:31 PM, Stephen Clark<sclark46@earthlink.net>  wrote:
>>      
>>> Hello,
>>>
>>> Problem:
>>> I have a two monitoring servers behind a a linux firewall, one is primary
>>> and one is backup.
>>> In the field we have units sending udp informational packet to the primary
>>> server. On the
>>> linux firewall I would like to copy this packet and change the destination
>>> address of the copied
>>> packet to point to the backup server. Is there a way to do this without
>>> writing any code?
>>>
>>> NOTE:
>>> Currently the firewall is FreeBSD and we accomplish this rather easily using
>>> ipfw along with natd, but we want to move to linux for our firewall.
>>>
>>>        
>> I think you can use tc action mirred to mirror the packets to a fake
>> NIC device ifb, and use tc action nat to dnat the packets received
>> from ifb.
>>
>>      
> Oh, iptables can also do it. Please see iptables target TEE and RAWNAT
> in xtables-addons. http://xtables-addons.sourceforge.net/
>
>    
Not to seem dumb - but I tried xtables TEE without any success. Could 
you provide a detailed
example?

Thanks,
Steve

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