RE: Router/Switches and viruses

THolman_at_toplayer.com
Date: 05/20/05

  • Next message: THolman_at_toplayer.com: "RE: Checkpoint SmartDefense"
    To: aseeker03@yahoo.com, focus-ids@securityfocus.com
    Date: Thu, 19 May 2005 20:11:28 -0400
    
    

    Hi Aseeker,

    I've worked with several worm breakouts and multiple DDOS attacks over the
    past year. Switches are generally not a problem (although bear in mind some
    low end switches will have problems with volume), but ROUTERS are.
    Most of the time, a low-end router will need to have ACLs disabled in order
    to stay up. A router is designed to forward traffic, rather than process
    the traffic according to an ACL, and then forward it. ACLs take up a lot of
    resource. If you then pass multiple-source volumes of traffic through such
    a router, you will kill it.
    I have seen a single desktop machine take out a switch though, but only as
    it was a source of a broadcast storm, and was plugged twice into the same
    switch...
    To prevent such an outage, make sure your L2 and L3 infrastructure can
    handle the maximum packets per second that each device can throw at it...
    If you run out of capacity, turn to Foundry or Extreme.
    To mitigate the affects of such a 'rogue' PC, ensure you have things like
    STP enable to cut out loops, and also segregate PCs into disparate LANs, and
    place an IPS in between to mitigate/stop the propagation of zero-day
    worms/viruses.
    From what you've said, it is more network design that is your potential
    problem. A NIDS and Sniffer will help you out in the long run as means of
    forensics, but only an IPS will PROTECT your networks if you deem that
    through risk analysis, this is protection you cannot do without.

    Regards,

    Tim

    -----Original Message-----
    From: Seek Knowledge [mailto:aseeker03@yahoo.com]
    Sent: 03 May 2005 22:41
    To: focus-ids@securityfocus.com
    Subject: Router/Switches and viruses

    Does anyone have any first-hand experience with a
    single infected desktop machine (or windows server for
    that matter) taking out a LAN switch? Would anyone
    have any stories from the trenches of an infected
    machine causing a directly connected router to stop
    functioning?

    If so, what could be done to prevent such an outage?
    What IDS/IPS strategy might one implement to prevent
    and or at least detect such an event?

    Thanks in advance.
    ASeeker

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  • Next message: THolman_at_toplayer.com: "RE: Checkpoint SmartDefense"

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