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Re: What do you want your ISP to block today?
From: "Gerardo Gregory" <ggregory () affinitas net>
Date: Sat, 30 Aug 2003 19:50:17 -0500

Well I understand why an ISP will filter these. But those things you mentioned are not software vendor vulnerabilities, or vulnerabilities of some proprietary protocol used only by desktop systems. Also the ISP will filter anything it feels it is a threat to it's own systems as that is where their own responsibility lies, and if they dont protect these they dont make any money. Because an ISP chooses to filter IANA reserved addresses (I am to argue that all do not perform this type of filtering, I would think that applying prefix lists, and null routes is what an ISP would do...not filter on source address...I have received packets at my edge with a IANA reserved address as the source), or turn off IP directed broadcasts, does not compare to applying filters every single time some vendor releases faulty code, or their code is exploited. These exploits affect the end user nodes of the ISP's customer, not the ISP itself (in a grand scale). The ISP is a business. G. Mark Borchers writes:
-----Original Message-----
From: owner-nanog () merit edu [mailto:owner-nanog () merit edu] On Behalf Of Gerardo Gregory Frankly I dont want any of my ISP's filtering any of my traffic. I think we need (especially enterprise administrators like myself) to take some responsibility, and place our own filters.

That's a popular sentiment which derives its facade of reasonableness
from the notion that ISP's ought to provide unencumbered pipes to the
Internet core. However, it doesn't bear close scrutiny.
Would you say that ISP's should not filter spoofed source addresses?
That they should turn off "no ip directed broadcast"?  Of course not,
because such traffic is clearly pathological with no redeeming social
The tough part for the ISP is to decide what other traffic types are
absolutely illegitimate and should therefore be subject to being
Verboten on the net.

Gerardo A. Gregory
Manager Network Administration and Security
402-970-1463 (Direct)
402-850-4008 (Cell)
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