Services Going Offline nf_conntrack table fulll

Discussion in 'Installation/Configuration' started by Jeff Usher, May 21, 2014.

  1. Jeff Usher

    Jeff Usher New Member

    For the last 2 nights my servers has shown services as being offline and the system log is full of the following:-

    nf_conntrack: table full, dropping packet


    Now I understand this may be a DOS or DDOS attack on the server.

    A reboot cures the problem but I can't reboot the server every night as that's impracticable.

    I should add that although the services are showing as offline - they are in fact online. i.e. the www service is showing as offline but all my sites are up.


    Any help in curing this would be appreciated. This never happened before the upgrade to and

    Many thanks

  2. Jeff Usher

    Jeff Usher New Member


    It looks like my server is being attacked nightly by some kind of stress attack. Here are the list of connections:-


    So it does look like some kind of dos attack and putting the system under loads of stress.

    Any recommendations for counter defence ?

  3. Croydon

    Croydon ISPConfig Developer ISPConfig Developer

  4. Jeff Usher

    Jeff Usher New Member

    Apologies, I thought the priority support threads were hidden so posted in the general support as well.

    Lesson learned.


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