[cod] Hey everyone

Fri Feb 24 11:05:35 EST 2012

If every Linux server had the iptables getstatus reflection throttle 
rule, it would be harder to do massive reflection attacks like this.

Unfortunately, even if every Linux admin did this, there would still be 
at least 20 servers that don't, and the attackers would just pick the 
ones that don't to do the attack.

Such a pain.

:(

On 02/23/2012 06:15 PM, NewLight Systems wrote:
> Yes that's very annoying . The problem is that is very easy to do a 
> distributed attack with this gameserver's bugs.
>
> And of course, any gameserver is probably on a dedicated line with 100 
> or 1000 MBPS bandwidth, so 20 "zombie" gameservers throwing reflection 
> attacks = 50 MBPS = 1 GBPS of distributed attack.
>
> I don't mind our cpus, are fast, but we are real capped at the 
> bottleneck that represents 1 GBPS of fast ethernet
>
> El 24/02/12 00:15, Boyd G. Gafford Ph.D. escribió:
>> Yep, thats getting towards the saturated side lol.  It must be a 
>> distributed DOS UDP flood, as I can't imagine many script kiddies 
>> with that kind of bandwidth for a single attack spoofing 20 IPs.
>>
>> At that point, a lot of your CPU is just handling the incoming IP 
>> packets.  Not much to do in that situation.  Even if you bonded four 
>> GbE's together, you're still looking at needing quite a chunk of CPU 
>> just to offload throwing away that 1Gbps.
>>
>> Even if you were to dynamically interact with your router to tell it 
>> to drop the packets, your incoming bandwidth would still be 
>> hammered.  It almost has to happen at the carrier (preferably at the 
>> carriers of the flooders) to do anything to help, and we all know how 
>> likely that is to happen unfortunately.
>>
>> Good luck,
>>
>> /Boyd/
>>
>>
>> On 02/23/2012 04:46 PM, NewLight Systems wrote:
>>> The problem is that we are receiving for example 1 GBPS attacks to 
>>> one IP from serveral sources ( maybe 15 - 20 ips )
>>>
>>> That means that 1 GB of inbound is occupied. We have iptables rules, 
>>> of course, but is affecting all services on that dedicated server
>>>
>>> El 23/02/12 23:42, Boyd G. Gafford Ph.D. escribió:
>>>> Hey there, thanks for responding.
>>>>
>>>> I'm not sure I understand what you mean by "the line is occupied 
>>>> anyway."  If you mean the bandwidth to the server is saturated by 
>>>> the flood, then yeah, its going to affect game play.  Fortunately 
>>>> most servers at data centers have high enough bandwidth to them 
>>>> that a typical attack doesn't saturate.
>>>>
>>>> If your game server port is the target of a single IP UDP flood 
>>>> attack, then typically an iptables drop rule handled by the kernel 
>>>> is more efficient than the game server itself, especially if the 
>>>> flooded packets are server commands that are being processed by the 
>>>> game server, which is sending out UDP reply packets.  That takes up 
>>>> much more CPU than a kernel-level packet drop.
>>>>
>>>> Under those circumstances, the cheap VPS we use in Dallas has 
>>>> endured 64Mbps attacks for hours and the game server is still very 
>>>> playable.  It would be nice if the flood was blocked at the router 
>>>> or carrier level, but still iptables is pretty amazing when the 
>>>> kernel drop is your last line of defense.
>>>>
>>>> Thanks,
>>>>
>>>> /Boyd/
>>>>
>>>>
>>>> On 02/23/2012 04:22 PM, NewLight Systems wrote:
>>>>> It's ok but this isn't working if the UDP floods to your server 
>>>>> because the line is occupied anyway.
>>>>>
>>>>> If you are the target, there's nothing you can do in a dedicated 
>>>>> server level.
>>>>>
>>>>> This type of attack ( allways if you are the target ) have to be 
>>>>> erradicated in a higher level ( router or carrier ) if you want to 
>>>>> preserve your connection
>>>>>
>>>>> El 23/02/12 23:12, Boyd G. Gafford Ph.D. escribió:
>>>>>> Hey everyone, EscapedTurkey told me about this group, and so I 
>>>>>> Just wanted to say a quick hello.
>>>>>>
>>>>>> I'm the guy who got frustrated enough with UDP flood attacks that 
>>>>>> I wrote ServerArk to deal with the majority of them.  If anyone 
>>>>>> has any questions about the program, or any ideas on what they 
>>>>>> would like to see in it in the future, by all means let me know.
>>>>>>
>>>>>> Since I've been using it on our JA (Q3 protocol) servers 
>>>>>> (http://elitewarriors.net) its blocked about 20 high volume 
>>>>>> attacks (one at 64Mbps) successfully over the past few months.  
>>>>>> As long as the source IP of the UDP flood is not random, it works 
>>>>>> really well.
>>>>>>
>>>>>> I have a few new ideas on flood detection on random IP attacks I 
>>>>>> will ping off your guys over the next few days to see what you think.
>>>>>>
>>>>>> Also kudos to whoever did the "I don't want to participate in 
>>>>>> reflection attacks" iptables rule that matches off of the 
>>>>>> 'getstatus' UDP packet payload.  If everyone who had a Q3 
>>>>>> protocol server (COD, JA, etc) had that rule running reflection 
>>>>>> attacks would be a LOT less potent.
>>>>>>
>>>>>> :)
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> /Boyd/
>>>>>>
>>>>>> /__________________________________
>>>>>> Boyd G. Gafford Ph.D.
>>>>>> Manager of Software Development
>>>>>> Westport Research Associates Inc.
>>>>>> 7001 Blue Ridge Blvd
>>>>>> Raytown, MO 64133
>>>>>> (816) 358-8990
>>>>>> drboyd at westportresearch.com
>>>>>> /
>>>>>>
>>>>>>
>>>>>> _______________________________________________
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>>>>>
>>>>> -- 
>>>>>
>>>>>
>>>>> *David Aguilar Valero*
>>>>>
>>>>> Dpto. Comercial y Soporte técnico
>>>>>
>>>>> NewLight Systems
>>>>>
>>>>> *Servidores de juegos, HW, Dedicados*
>>>>>
>>>>>
>>>>> *crk01 at nls.es* <mailto:c>
>>>>>
>>>>> crk01 at newlightsystems.com <mailto:crk01 at newlightsystems.com>
>>>>>
>>>>> tecnico at newlightsystems.com <mailto:tecnico at newlightsystems.com>
>>>>>
>>>>> #NewLight_Systems @ irc-hispano.org
>>>>>
>>>>> *www.newlightsystems.com* <http://www.newlightsystems.com/>
>>>>>
>>>>> *www.nls.es* <http://www.nls.es/>
>>>>>
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>>> -- 
>>>
>>>
>>> *David Aguilar Valero*
>>>
>>> Dpto. Comercial y Soporte técnico
>>>
>>> NewLight Systems
>>>
>>> *Servidores de juegos, HW, Dedicados*
>>>
>>>
>>> *crk01 at nls.es* <mailto:c>
>>>
>>> crk01 at newlightsystems.com <mailto:crk01 at newlightsystems.com>
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>>
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> -- 
>
>
> *David Aguilar Valero*
>
> Dpto. Comercial y Soporte técnico
>
> NewLight Systems
>
> *Servidores de juegos, HW, Dedicados*
>
>
> *crk01 at nls.es* <mailto:c>
>
> crk01 at newlightsystems.com <mailto:crk01 at newlightsystems.com>
>
> tecnico at newlightsystems.com <mailto:tecnico at newlightsystems.com>
>
> #NewLight_Systems @ irc-hispano.org
>
> *www.newlightsystems.com* <http://www.newlightsystems.com/>
>
> *www.nls.es* <http://www.nls.es/>
>
> This email and any files or attachments transmitted with it are 
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