Re: rp_filter

Grant Taylor <[email protected]> wrote:

>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.

	I believe they're also counted in the "in_martian_src" column of
/proc/net/stat/rt_cache.

	-J

>> 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. . . .
>unix || die

---
	-Jay Vosburgh, [email protected]