return-icmp() relative question to ipf rule.

jhell jhell at
Wed Oct 28 17:22:54 UTC 2009

On Wed, 28 Oct 2009 04:23, remko@ wrote:
> On Oct 26, 2009, at 4:02 PM, jhell wrote:
>> On Mon, 26 Oct 2009 09:18, remko@ wrote:
>>> On Oct 10, 2009, at 4:09 AM, jhell wrote:
>>>> I have a rule I used in ipfilter probably around 2 or so years ago and I 
>>>> am now getting around to trying to implement in it my pf rules. So far 
>>>> any results I have achieved have failed with no response back from the 
>>>> server and get dropped.
>>>> The rule in ipf syntax:
>>>> block return-icmp-as-dest(13) in log first quick proto icmp all icmp-type 
>>>> 8
>>>> The above ipf rule returns a result of "Destination Administratively 
>>>> Prohibited" when ping'd
>>>> The following pf syntax:
>>>> block return-icmp(3,13) in quick inet proto icmp from any to any 
>>>> icmp-type 8 code 0
>>>> The above pf rule returns a result of "Nothing ........" when ping'd
>>>> Just to be sure I wasn't mucking up the chain of rules I added this as 
>>>> the only rule to test it out and have achieved the same result multiple 
>>>> times on a test machine.
>>>> Can anyone shed some light on the syntax and help me out with getting 
>>>> this rule to make the system respond to a echo request with admin-prohib 
>>>> as the destination system ?
>>>> Thanks
>>> *click* (the light is on)
>>>        Options returning ICMP packets currently have no effect if pf(4)
>>>        operates on a if_bridge(4), as the code to support this feature has
>>>        not yet been implemented.
>>> from the Manual page. I think that answers the question?
>> Thanks Remko,
>> No I'm not using if_bridge(4) here, nor any bridge for that matter. I have 
>> tested this directly from interface -> interface with a patch cable 
>> thinking that the click that I heard from the light above would actually 
>> turn something on but was just throwing a breaker.
> OK, yes I understand what you mean. I over-read the bridge part. My apologies 
> for the confusion this caused. I am not sure whether it then should or should 
> not work though. One thing that I noticed is that you speak about
> 'it was in IPF and it isn't in PF', please keep in mind that PF is a complete 
> rewrite and looks similiar to IPF with syntax etc. Features found there are 
> no guarantee that it will be in PF as well. Doesn't make up the fact that the
> documentation indeed talks about it being possible and seemingly impossible 
> to do it.
> I added Max to the discussion, he might be able to tell whether or not this 
> is integrated and whether it should work at all :-)
> Thanks for catching my misread part!

Hey its no problem at all, I appreciate the feedback because I thought 
that possibly I might have missed something that wasn't allowing it to work 
but I have tried all kinds of trickery around the likes of adding pass out 
all rules of type ICMP with specific codes and such before and after the 
rule in question and nothing seems to do it. So some input on this was 
better than none at all. Thanks for your response and can't wait for some 
more interaction on this thread as this has now just become a annoying 
unreachable objective for me.

Best regards.


  ;;!jhell         2048R/89D8547E 2009-09-30
  ;; BSD since FreeBSD 4.2    Linux since Slackware 2.1
  ;; 85EF E26B 07BB 3777 76BE  B12A 9057 8789 89D8 547E

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