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.