nanog mailing list archives
Re: Todd Underwood was a little late
From: William Herrin <bill () herrin us>
Date: Fri, 18 Jun 2010 09:06:56 -0400
On Fri, Jun 18, 2010 at 8:37 AM, Steve Bertrand <steve () ipv6canada com> wrote:
On 2010.06.17 17:10, William Herrin wrote:Reverse path filtering + asymmetric routing = epic fail. Jon did say Multihomed customer.If all IP blocks are tied down to null, and urpf is enabled in loose mode on an interface, it will catch cases where someone is sourcing traffic to you using IPs from the unassigned space that you have in your free pools.
Hi Steve, I'm not sure what that accomplishes. It doesn't close any doors. With loose-mode RPF he can still forge packets from any address actually in use.
Every month or so I re-route my blackholed traffic to a sinkhole, and more often than not, I see some ingress traffic from my unassigned space.
You'd be better off pointing the forward routes at a packet logger so you can gain some insight into who is scanning the network, particularly when the scanner actually is internal. Regards, Bill Herrin -- William D. Herrin ................ herrin () dirtside com bill () herrin us 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/> Falls Church, VA 22042-3004
Current thread:
- Re: Todd Underwood was a little late, (continued)
- Re: Todd Underwood was a little late Mark Andrews (Jun 16)
- Re: Todd Underwood was a little late Jon Lewis (Jun 16)
- Re: Todd Underwood was a little late Mark Andrews (Jun 16)
- Re: Todd Underwood was a little late Roy (Jun 16)
- Re: Todd Underwood was a little late Garrett Skjelstad (Jun 16)
- Re: Todd Underwood was a little late Brian Feeny (Jun 17)
- Re: Todd Underwood was a little late William Herrin (Jun 17)
- Re: Todd Underwood was a little late Steve Bertrand (Jun 18)
- Re: Todd Underwood was a little late Chris Adams (Jun 18)
- Re: Todd Underwood was a little late Steve Bertrand (Jun 18)
- Re: Todd Underwood was a little late William Herrin (Jun 18)
- Re: Todd Underwood was a little late Steve Bertrand (Jun 18)
- Re: Todd Underwood was a little late William Herrin (Jun 18)
- Re: Todd Underwood was a little late Jon Lewis (Jun 16)
- Re: Todd Underwood was a little late Mark Andrews (Jun 16)
- Re: Todd Underwood was a little late Owen DeLong (Jun 17)
- Re: Todd Underwood was a little late Frank Habicht (Jun 18)
- Re: Todd Underwood was a little late Christopher Morrow (Jun 17)
- Re: Todd Underwood was a little late Todd Underwood (Jun 17)
- RE: Todd Underwood was a little late Lee Howard (Jun 18)
- Re: Todd Underwood was a little late Michael Dillon (Jun 19)