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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: SMURF amplifier block list
Why don't use the filter deny icmp any 0.0.0.255 255.255.255.0 echo-request on the incoming lines? It just block 99.999% of this smurf amplifiers; and I hardly think someone eve sence this restriction for the real PING tests. ??? On Fri, 17 Apr 1998, Dean Anderson wrote: > Date: Fri, 17 Apr 1998 18:09:08 -0400 > From: Dean Anderson <[email protected]> > To: [email protected] > Cc: [email protected] > Subject: Re: SMURF amplifier block list > > > Does no ip directed broadcast really work? > > Yes. It works. > > And it works for whatever your particular netmask or broadcast address > happens to be, which is what's important. > > The only time you shouldn't do it globally is when some other network > really needs to see broadcasts. For example, If we manage a client's > network with HP OpenView over the internet, we need to be able to send them > directed broadcasts, so that OpenView host discovery will work. Patrol > works the same way, as do other products. In this case you can't use the > "no ip directed broadcast" switch, but you can still set up access rules > which do the same thing except for the permitted network. > > Bottom line is that you should protect your network from people who would > either abuse it via smurfing, or simply have no business looking for hosts > on your network. You have the tools to do it. > > --Dean > > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > Plain Aviation, Inc [email protected] > LAN/WAN/UNIX/NT/TCPIP/DCE http://www.av8.com > We Make IT Fly! (617)242-3091 x246 > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > > 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)
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