RE: ICMP/SYN Flood

From: Whiteside, Larry [contractor] (BAE14_at_SPHQ.SSP.NAVY.MIL)
Date: 05/22/03

  • Next message: Sebastian Jaenicke: "Re: ICMP/SYN Flood"
    Date: Thu, 22 May 2003 15:36:11 -0400
    To: "Muhammad Naseer Bhatti" <mail-lists@digitallinx.com>
    
    

    Everything you are seeing should be blocked at the router. The fact that they aren't tell me a lot more is not either. Scary! Anyway, go to NSA's website and have them download their router config guide. It is what I use and is GREAT. It will give them all the things needed to lock down their router. It is very simple to follow along and they give you a lot of commands. If they cannot use this then God help you all!

    http://www.nsa.gov/snac/cisco/download.htm

    L
    ***************************
    Larry Whiteside Jr.
    Sr. Security Engineer

    -----Original Message-----
    From: Muhammad Naseer Bhatti [mailto:mail-lists@digitallinx.com]
    Sent: Wednesday, May 21, 2003 10:47 PM
    To: incidents@securityfocus.com
    Subject: ICMP/SYN Flood

    Hi list ..

    I am experiencing a bad DDoS attack toward one of my server. The attack is
    pointed to only 1 IP on which a governmental site is hosted. Seems some
    folks don't like the site to stay up. As far as the Server (Linux) security
    is concerned, I am able to make that up serving all requests without any
    hesitation. My network with which I am connected to is poorly configured and
    allowing the DDoS attack to pass thru their routers. I am getting two kind
    of attacks here:

    - ICMP Flood
            Simple ICMP flood from various spoofed hosts. This I know can be
    blocked on the router for the particular IP. Unfortunately the network guys
    are still not able to do that.

    - SYN Flood
            Interesting thing. Loots of SYN requests from these kind of
    network/broadcasts towards port 80 only.

    37.72.0.0
    128.89.0.0
    173.66.0.0
    37.155.0.0
    177.225.0.0
    37.94.0.0
    36.162.0.0
    117.77.0.0
    151.162.0.0
    36.216.0.0
    134.248.0.0
    175.129.0.0

    And the list goes oon .. The question I want to ask here, is the
    network/router poorly configured at my NOC which is allowing
    broadcasts/networks to pass through it? If so, how can I assist them to fix
    it? I am not a Cisco guru, so might need someone to give me some hints so
    that I can pass that to the poor NOC techs.

    Any help would be appreciated.

    Thanks,

    Muhammad Naseer

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  • Next message: Sebastian Jaenicke: "Re: ICMP/SYN Flood"

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