nanog mailing list archives
Re: Network Operators and smurf
From: Havard.Eidnes () runit sintef no
Date: Sat, 25 Apr 1998 19:37:36 +0200
Wait; all traffic is coming in one interface. The CEF thing will have no effect if the spoofed source address is a real network.
"The CEF thing" configuration from my first message in this thread does the following: For each packet entering an interface with "ip verify unicast reverse-path" turned on, the router will look up the source address from the IP packet in the CEF table and find the interface (or set of interfaces) it would use to route back to the source. If the incoming interface for the actual packet is not among those returned by the "reverse-path" lookup, the packet is dropped on the floor.
From my point of view this is exactly the sort of functionality
which is needed to prevent us from being the host (originator) of a Smurf attack (or more generally from attacks involving IP address spoofing), as in the case of a Smurf attack packets with the victim's source address entering from the wrong interface will be dropped on the floor. If you still think this doesn't help or isn't useful, I propose that we take it to private e-mail (?). - HÃ¥vard
Current thread:
- Re: Network Operators and smurf, (continued)
- Re: Network Operators and smurf Jay R. Ashworth (Apr 24)
- Re: Network Operators and smurf Christopher Neill (Apr 26)
- Re: Network Operators and smurf Robert Sanders (Apr 26)
- Re: Network Operators and smurf Phil Howard (Apr 26)
- Re: Network Operators and smurf Havard . Eidnes (Apr 25)
- Re: Network Operators and smurf Al Reuben (Apr 25)
- Re: Network Operators and smurf Havard . Eidnes (Apr 25)
- Re: Network Operators and smurf Al Reuben (Apr 25)
- Re: Network Operators and smurf Havard . Eidnes (Apr 25)
- Re: Network Operators and smurf Al Reuben (Apr 25)
- Re: Network Operators and smurf Havard . Eidnes (Apr 25)
- Re: Network Operators and smurf Phil Howard (Apr 26)
- Re: Network Operators and smurf Phil Howard (Apr 26)
- Re: Network Operators and smurf Brian Holt (Apr 25)
- Re: Network Operators and smurf Alex P. Rudnev (Apr 27)
- RE: Network Operators and smurf barton (Apr 25)
- RE: Network Operators and smurf Craig A. Huegen (Apr 26)
- Re: Network Operators and smurf Karl Denninger (Apr 26)
- Re: Network Operators and smurf Jason Lixfeld (Apr 26)