nanog mailing list archives
RE: Network Operators and smurf
From: Doug Stanfield <DOUGS () oceanic com>
Date: Mon, 27 Apr 1998 07:22:06 -1000
Don't assume it's not needed for the 75xx, or anything else for that matter. Many networks are single connected to routers that are also acting multihomed to core providers and these boxes are being used. Doug Stanfield Oceanic Cable Data Networking Manager 200 Akamainui St. dougs () oceanic com Mililani, HI 96789 Usially the low-end traffic is symmetrical. The problem is that CEF code and other anty-frauding realisations are appearing for the high-end routers, white they are nessesary for the low-end routers and useless for the core routers. For cisco, we need this future for 4500/4700/3640/2511 ASAP, 720x slightly, and don't need it for 75xx at all. On Sat, 25 Apr 1998, Al Reuben wrote: > Date: Sat, 25 Apr 1998 12:30:50 -0400 (EDT) > From: Al Reuben <alex () nac net> > To: Havard.Eidnes () runit sintef no > Cc: jra () scfn thpl lib fl us, nanog () merit edu > Subject: Re: Network Operators and smurf > > > > This should (naturally) be implemented where routing is symmetric > > and where a "reverse-path check" (looking up the source address in > > the routing table to find the "expected" incoming interface and > > checking whether the packet did indeed enter through that interface) > > The big question is, what do you do if most of your traffic _is_ > asymetrical? I mean, a more basic check could be, "Does the network that > this packet was sourced from exist *at all*?", or "Do I have a route back > to the source network through *any* interface?" > > That would cut down on a good amount of spoofing, like the idiots who > spoof from 1.1.1.1 etc. > > > Aleksei Roudnev, Network Operations Center, Relcom, Moscow (+7 095) 194-19-95 (Network Operations Center Hot Line),(+7 095) 239-10-10, N 13729 (pager) (+7 095) 196-72-12 (Support), (+7 095) 194-33-28 (Fax)
Current thread:
- Re: Network Operators and smurf, (continued)
- Re: Network Operators and smurf Jason Lixfeld (Apr 26)
- Re: Network Operators and smurf Karl Denninger (Apr 26)
- Re: Network Operators and smurf Daniel R Ehrlich (Apr 26)
- Re: Network Operators and smurf Dalvenjah FoxFire (Apr 26)
- Re: Network Operators and smurf D'Arcy J.M. Cain (Apr 27)
- Re: Network Operators and smurf (UTSA) Bryan Bradsby (Apr 27)
- Re: Network Operators and smurf (UTSA) Karl Denninger (Apr 27)
- Re: Network Operators and smurf (UTSA) D'Arcy J.M. Cain (Apr 28)
- Re: Network Operators and smurf Michael Dillon (Apr 26)