Merit Network
Can't find what you're looking for? Search the Mail Archives.
  About Merit   Services   Network   Resources & Support   Network Research   News   Events   Home

Discussion Communities: Merit Network Email List Archives

North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: UUNet Offer New Protection Against DDoS

  • From: Patrick W.Gilmore
  • Date: Wed Mar 03 18:28:33 2004

On Mar 3, 2004, at 5:51 PM, Lumenello, Jason wrote:

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.
A lot of people seem to be doing this.

Mind if I ask what's the harm of letting customers announce /32 or /29s into your core as long as you filter at your borders?

The additional prefixes are not going to kill your routers, and it allows the customer more finely tuned traffic controls. IOW: Seems there is some utility and no harm.

--
TTFN,
patrick





Discussion Communities


About Merit | Services | Network | Resources & Support | Network Research
News | Events | Contact | Site Map | Merit Network Home


Merit Network, Inc.