rtfree: 0xc741ee88 has 1 refs

Stefan Lambrev stefan.lambrev at moneybookers.com
Wed Nov 7 02:55:32 PST 2007


I compiled kernel with all debug stuff in it, but I'm not sure what to 
do next :)
I have serial console to the server so I boot with -dDh and enter debig 
I can enter at debug mode at any time now, so any idea how to catch what 
trigger this rtfree ? :)
I'm following steps from 
What info should I provide?

Stefan Lambrev wrote:
> Hi,
> Just to confirm that after reboot I'm seeing imediately rtfree: %P has 
> 1 refs.
> I'll recompile kernel with debug and will try to find out more.
> Stefan Lambrev wrote:
>> Hi,
>> Per olof Ljungmark wrote:
>>> Stefan Lambrev wrote:
>>>> Hi,
>>>> Sorry to reply to myself, but I found that the problem exist only 
>>>> if the GW is carp interface, e.g. sits on carp0 on default 
>>>> GW.
>>>> I'm still testing how to reproduce this in my test lab and will 
>>>> fill a PR.
>>>> Stefan Lambrev wrote:
>>>>> Hi,
>>>>> I see rtfree: 0xc741ee88 has 1 refs with freebsd releng_7 (i386) 
>>>>> from today.
>>>>> I think it's easy reproducible. What I have is:
>>>>> releng_7 ( -> default GW (
>>>>> on default GW I have route to ->
>>>>> so everytime when try to contact someone from 
>>>>> I see:
>>>>> rtfree: 0xc741ee88 has 1 refs
>>>>> if I add direct route on to through 
>>>>> the message will go away.
>>>>> Should I ignore this msg for now, or should I expect kernel panic 
>>>>> soon? :)
>>> Just FYI, I see this on a few boxes including the 7-BETA2 I'm 
>>> writing this on. None of them has a carp interface though. What I 
>>> find interesting here is that none of them are able to run a SMP 
>>> kernel without crashing (no panic, they're just frozen completely).
>>> Perhaps it is a coincidence, I don't know, but I am very interested 
>>> in your findings and have testbeds if you need.
>>> --per
>> In the begging I thought this is very easy reproducible, but it isn't :)
>> In my situation the IP of the default GW sits on carp interface (the 
>> host have nothing to do with carp)
>> and when the host receive icmp redirect messages they actually are 
>> send from the IP of the netwrok card of the GW (not the IP that sits 
>> on carp0)
>> then the host things that those icmp type 5 are spoofed and just 
>> ignore them and do not add shorter route.
>> In this situation after reboot the hosts start to moan about rtfree, 
>> so I played with routes and settings, added manually routes and now 
>> when I restore everything to previous state
>> I do not see anymore rtfree warnings. So may be once the route is 
>> created manually and then removed, wrong call of rtfree is not 
>> triggered anymore.
>> I'll reboot the host latter to see if this easy reproducible at least 
>> on reboot, and if it is, I'll compile debug kernel and will run 
>> backtrace.
>> The other thing that bother me is that icmp redirects are not send 
>> from the carpIP, but from the real interface's IP? Isn't this a bug, 
>> or it is normal behavior?


Best Wishes,
Stefan Lambrev
ICQ# 24134177

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