North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: SMURF amplifier block list - READ THIS
On Wed, Apr 15, 1998 at 01:04:19PM -0600, Dax Kelson wrote: > This isn't quite as bad as it sounds, because in nearly all cases, the > *OUTGOING* bandwidth from the amplification network will be *MUCH* less > then the aggregate traffic produced by all the devices on the > amplification LAN. > > So what ends up happening in most cases, is that 20-90Mpbs of traffic > slams into the router interface capable of only 1.5/3/6/9Mbps of outgoing > traffic. Still, though a modem or ISDN connection being able to summon > 1.5-9Mpbs is quite a problem. Well, most of the real "problem" smurf sites are DS-3 connected or better. The little ones don't bother us. > There has been very little mention of anti-SPOOF measures in this thread > which is surprising. Try to get people to do that.... we have, its pointless. > IP SPOOFing is *THE SOURCE* of all the major problems: > > SYN-FLOOD > TEARDROP and variants > SMURF > What's Next??? > > > Solutions: > > Validate all traffic leaving your networks to be sure the IP source is > from one of your networks. > > Everyone from the tier 1 providers on down should write that requirement > into all their connection agreements. > > Further, the fact is that nearly *ALL* such attacks (attacks that use > IP-SPOOFing as a requirement) are launched from dial-up connections. > > If would be relatively easy to have a *DRAMATIC* reduction in attacks if > the dialup equipment vendors would release software updates with *DEFAULT* > anti-spoof filters applied to dialup connections. > > Put some pressure on your vendors, nearly all dialup ports are made by > either Lucent/Livingston, Ascend, and 3COM/USR. > > I've been asking Livingston for two years for this feature. > > Dax Kelson > Internet Connect, Inc. Yeah, well, why not find a way to ram it down UUNET, SPRINT, MCI's, and the rest of the national's throats first? We already do this - its not a perfect filter, but it will only let you transmit packets with sources that COULD possibly come from us. -- -- Karl Denninger ([email protected])| MCSNet - Serving Chicagoland and Wisconsin http://www.mcs.net/ | T1's from $600 monthly / All Lines K56Flex/DOV | NEW! Corporate ISDN Prices dropped by up to 50%! Voice: [+1 312 803-MCS1 x219]| EXCLUSIVE NEW FEATURE ON ALL PERSONAL ACCOUNTS Fax: [+1 312 803-4929] | *SPAMBLOCK* Technology now included at no cost
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