[Arm-dev] System hung yesterday

Robert Moskowitz rgm at htt-consult.com
Mon Feb 6 13:57:13 UTC 2017



On 02/06/2017 08:44 AM, Manuel Wolfshant wrote:
> On 02/06/2017 03:16 PM, Robert Moskowitz wrote:
>> My server hung yesterday.  I did not notice it; at this stage in the 
>> game, I should be much more aware...
>>
>> I looked into /var/log/messages and my last entry was:
>>
>> Feb  5 15:03:46 medon kernel: conntrack: generic helper won't handle 
>> protocol 47
>> . Please consider loading the specific helper module.
>>
>> So I don't know if someone knocked me over with a GRE based attack, 
>> if the drive is bad, if the board is bad, or the OS has a problem.
>>
>> So simple things to start with.  I see an earlier GRE warning in 
>> messages:
>>
>> Feb  5 03:29:49 medon kernel: conntrack: generic helper won't handle 
>> protocol 47. Please consider loading the specific helper module.
>>
>> So it is probably not a stack problem with attacking GRE bots. BTW, 
>> is there some 'easy' way to just block these?
> $IPTABLES -A INPUT  -i $EXTERNAL_INTERFACE -p gre -j REJECT

Thanks, but how do I do that in firewall-cmd?

# firewall-cmd --list-all
public (active)
   target: default
   icmp-block-inversion: no
   interfaces: eth0
   sources:
   services: dhcpv6-client http https
   ports: 1234/tcp
   protocols:
   masquerade: no
   forward-ports:
   sourceports:
   icmp-blocks:
   rich rules:




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