nanog mailing list archives
Re: smurf's attack..i
From: Steve Noble <steve () altrina exodus net>
Date: Fri, 5 Sep 1997 14:40:29 -0700 (PDT)
If you are going to filter, you can just filter ICMP for now, thats the major protocol used in the attack, that way you are only slightly affecting those who might have a .255 address on one of their machines. so access-list xxx deny icmp any 0.0.0.255 255.255.255.0 and access-list xxx deny icmp any 0.0.0.0 255.255.255.0 are pretty safe ones. Oh yes, if you didn't notice already they are using the .0 network address, and from what i've seen the amount of attacks launched using .0 as compared to .255 have been steadily rising. And while turning off ip directed broadcast will mostly take care of this issue, it's only a complete solution if your customers also do it, so filtering is still a good idea IMHO. On Fri, 5 Sep 1997, Phil Howard wrote:
Randy Bush writes...access-list XXX deny ip any 0.0.0.255 255.255.255.0You must be kidding. Why not access-list XXX deny ip any 0.0.0.42 255.255.255.0I like... access-list XXX deny ip any 0.0.0.1 255.255.255.254 ...better. -- Phil Howard KA9WGN +-------------------------------------------------------+ Linux Consultant | Linux installation, configuration, administration, | Milepost Services | monitoring, maintenance, and diagnostic services. | phil at milepost.com +-------------------------------------------------------+
Current thread:
- Re: smurf's attack..., (continued)
- Re: smurf's attack... Michael K. Sanders (Sep 05)
- Re: smurf's attack... DAVE NORDLUND (Sep 05)
- Re: smurf's attack... Jordyn A. Buchanan (Sep 05)
- Re: smurf's attack... Michael K. Sanders (Sep 05)
- Re: smurf's attack... Randy Bush (Sep 05)
- Re: smurf's attack... Dave Andersen (Sep 06)
- Re: smurf's attack... Randy Bush (Sep 05)
- Message not available
- Re: smurf's attack... Jay R. Ashworth (Sep 05)
- Re: smurf's attack... Dave Bergum (Sep 05)
- Re: smurf's attack... Phil Howard (Sep 05)
- Re: smurf's attack..i Steve Noble (Sep 05)
- Re: smurf's attack... Wayne Bouchard (Sep 05)