nanog mailing list archives
RE: The impending DDoS storm
From: "Darren Richer" <dricher () personainc ca>
Date: Thu, 14 Aug 2003 14:35:36 -0400
Assuming cable operators have enabled: cable source-verify or cable source-verify dhcp for Cisco IOS based CMTSes, spoofing in the same subnet will be dropped at the CMTS. Other vendors have similar features to mitigate this possibility. The worst a cable operator would likely from this see is some upstream saturation since the packets aren't dropped until the CMTS. D. --- Darren Richer Director of Telecommunications Persona Communications Inc. -----Original Message----- From: owner-nanog () merit edu [mailto:owner-nanog () merit edu]On Behalf Of Michael Painter Sent: August 14, 2003 2:16 PM To: flyman2 () corp earthlink net; nanog () merit edu Subject: Re: The impending DDoS storm http://www.dslreports.com/forum/remark,7652257~root=security,1~mode=flat;sta rt=0 ----- Original Message ----- From: "Josh Fleishman" <flyman2 () corp earthlink net> To: <nanog () merit edu> Sent: Thursday, August 14, 2003 5:24 AM Subject: RE: The impending DDoS storm
Has anyone determined a method for triggering the DOS attack manually? We've attempted this by changing an infected machine's clock, however it did not work on our test box. If anyone has triggered the attack, do you have a copy of the sniffed data stream? It sounds like uRPF is going to be of very little benefit to blocking the attack if the spoofed addresses come from the infected host's subnet/parent subnet. -Josh -----Original Message----- From: owner-nanog () merit edu [mailto:owner-nanog () merit edu] On Behalf Of Mark Vallar Sent: Wednesday, August 13, 2003 7:18 PM To: nanog () merit edu Subject: Re: The impending DDoS storm Jack Bates Wrote:I have no affiliation with Microsoft, nor do I care about their services or products. What I do care about is a worm that sends out packets uncontrolled. If there is the possibility that this "planned" DOS will cause issues with my topology, then I will do whatever it takes to stop it. The fact that user's can't reach windowsupdate.com is irrelevant.There will most likely be issues with a lot of networks. I had a glimpse of what is to come on the 16th on Tuesday. We have a firewall customer that had an infected machine behind the firewall and the RTC clock was set incorrectly to 8/16. The firewall was *logging* ~50 attempts per second trying to connect on port 80 to windowsupdate.com. Since the worm was sending from a spoofed source address the firewall was denying the packets. This customers network is a /24 out of traditional Class B space and I was seeing random source addresses from almost every IP out of the /16. This is not a forensic analysis, just what I observed in the firewall logs. Is it a coincidence that 8/16 is a Saturday....I think not. A lot less personal on-site to deal with possible issues. -Mark Vallar
Current thread:
- Re: The impending DDoS storm, (continued)
- Re: The impending DDoS storm Aaron Hopkins (Aug 13)
- Re: The impending DDoS storm Jeff Kell (Aug 14)
- RE: The impending DDoS storm Eric Germann (Aug 13)
- RE: The impending DDoS storm McBurnett, Jim (Aug 13)
- Re: The impending DDoS storm Jack Bates (Aug 13)
- Re: The impending DDoS storm Mark Vallar (Aug 13)
- Re: The impending DDoS storm Jack Bates (Aug 13)
- RE: The impending DDoS storm Josh Fleishman (Aug 14)
- RE: The impending DDoS storm Christopher Chin (Aug 14)
- RE: The impending DDoS storm Kevin Houle (Aug 14)
- Re: The impending DDoS storm Michael Painter (Aug 14)
- RE: The impending DDoS storm Darren Richer (Aug 14)