Todd Underwood was a little late

Garrett Skjelstad garrett at skjelstad.org
Thu Jun 17 00:07:10 CDT 2010


RFC 2827 anyone?

On Wed, Jun 16, 2010 at 9:38 PM, Roy <r.engehausen at gmail.com> wrote:

> On 6/16/2010 7:43 PM, Jon Lewis wrote:
>
>> On Thu, 17 Jun 2010, Mark Andrews wrote:
>>
>>  Why was this traffic hitting your DNS server in the first place?  It
>>> should
>>> have been rejected by the ingress filters preventing spoofing of the
>>> local
>>> network.
>>>
>>
>> When I ran a smaller simpler network, I did have input filters on our
>> transit providers rejecting packets from our IP space.  With a larger
>> network, multiple IP blocks, numerous multihomed customers, some of which
>> use IP's we've assigned them, it gets a little more complicated to do.
>>
>> I could reject at our border, packets sourced from our IP ranges with
>> exceptions for any of the IP blocks we've assigned to multihomed customers.
>>  The ACLs wouldn't be that long, or that hard to maintain.  Is this common
>> practice?
>>
>> -
>>
>
> Sounds like a good use of URPF.
>
>
>



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