[LARTC] Re: "dst cache overflow" messages and crash

[Frédéric Massot]

Ivan Vladimirov wrote:
> Frédéric Massot wrote:
>> Hi,
>>
>> I regularly have errors (kernel: dst cache overflow) and crash of a
>> firewall under Linux 2.6.17 and the route patch from Julian Anastasov.
>>
>> With rtstat I see that the route cache size increases regularly without
>> never decreasing.
>>
>> I have this parameters:
>> fw:/proc/sys/net/ipv4/route# grep . *
>> error_burst:1250
>> error_cost:250
>> gc_elasticity:15
>> gc_interval:60
>> gc_min_interval:0
>> gc_min_interval_ms:500
>> gc_thresh:4096
>> gc_timeout:300
>> max_delay:10
>> max_size:65536
>> min_adv_mss:256
>> min_delay:2
>> min_pmtu:552
>> mtu_expires:600
>> redirect_load:5
>> redirect_number:9
>> redirect_silence:5120
>> secret_interval:600
>>
>> I can increase the maximum size of the cache, but that will do nothing
>> but delay the crash.
>>
>> Can you help me?
>>
>> Regards.
> max_size=65536
> is to low increase size to 256k

Hi,

I supervised the system during a few weeks with slabtop and rtstat.

What I could see, it is that the ip_dst_cache cache grow without never 
being cleaned by the garbage collector.

At the end of a few days, the traffic is slowed down and the customer 
restart the firewall. When the cache reaches its maximum value there is 
the error message (kernel: dst cache overflow) and the traffic is really 
disturbed.

I use the Linux kernel 2.6.17 and the route patch from Julian Anastasov.

- The bug comes from the kernel or the patch?

- Do you know if this bug were corrected in the new versions of the kernel?

Regards.
-- 
==============================================
|              FRÉDÉRIC MASSOT               |
|     http://www.juliana-multimedia.com      |
|   mailto:frederic at juliana-multimedia.com   |
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