nanog mailing list archives

RE: UUNet Offer New Protection Against DDoS


From: "Lumenello, Jason" <jlumenello () xo com>
Date: Wed, 3 Mar 2004 17:51:35 -0500


I struggled with this, and came up with the following.

We basically use a standard route-map for all customers where the first
term looks for the community. The customer also has a prefix-list on
their neighbor statement allowing their blocks le /32. The following
terms (term 2 and above) in the route-map which do NOT look for the
customer discard community, have a different standard/generic
prefix-list evaluation which blocks cruft and permits 0.0.0.0/0 ge 8 le
24.

By doing this, I only accept a customer /32 from his dedicated
prefix-list when it has the DOS discard community, otherwise I catch
them with the ge 8 le 24 in the following terms.

Jason Lumenello
IP Engineering
XO Communications

-----Original Message-----
From: owner-nanog () merit edu [mailto:owner-nanog () merit edu] On Behalf
Of
Stephen J. Wilcox
Sent: Wednesday, March 03, 2004 3:48 PM
To: james
Cc: nanog () merit edu
Subject: Re: UUNet Offer New Protection Against DDoS



I'm puzzled by one aspect on the implementation.. how to build your
customer
prefix filters.. that is, we have prefix-lists for prefix and length.
Therefore
at present we can only accept a tagged route for a whole block.. not
good
if the
announcement is a /16 etc !

Now, I could do as per the website at secsup.org which means we have a
route-map
entry to match the community before the filtering .. but that would
allow
the
customer to null route any ip.

What we need is one to allow them to announce any route including more
specifics of the prefix list - how are folks doing this?

Steve

On Wed, 3 Mar 2004, james wrote:


Global Crossing has this, already in production.
I was on the phone with Qwest yesterday & this was one
of this things I asked about. Qwest indicated they are
going to deploy this shortly. (i.e., send routes tagged with
a community which they will set to null)


James Edwards
Routing and Security
jamesh () cybermesa com
At the Santa Fe Office: Internet at Cyber Mesa
Store hours: 9-6 Monday through Friday
505-988-9200 SIP:1(747)669-1965




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