Re: rp_filter

On 07/13/2018 09:23 AM, Leroy Tennison wrote:
> Is there a definitive way to tell that rp_filter is dropping traffic (in 
> this case echo request) other than disabling it and seeing the expected 
> traffic (echo reply)?  I tried an iptables packet trace but I either did 
> it wrong or it showed nothing.  The only indications I have right now are:

Check dmesg.  That's the most reliable place I've seen for logs about 
(so called) "martian" packets.

> No firewall rules blocking traffic but no replies either.

It seems like reverse path filtering operates at a lower layer before 
IPTables.

> The problem is subnet-specific (only occurs on a directly-connected 
> subnet).

Odd.



-- 
Grant. . . .
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