On Wed, Oct 30, 2002 at 08:02:13PM +0100, Lars Erik Gullerud wrote:
On Wed, 2002-10-30 at 16:44, variable@ednet.co.uk wrote:
Therefore, would it be a reasonable suggestion to ask router vendors to source address filtering in as an option[1] on the interface and then move it to being the default setting[2] after a period of time? This appeared to have some success with reducing the number of networks that forwarded broadcast packets (as with "no ip directed-broadcast"). [snip]
[1] For example, an IOS config might be:
interface fastethernet 1/0 no ip forged-source-address
Well, this already exists, doesn't it? Try the following on your customer-facing interface:
ip verify unicast source reachable-via rx
[2] Network admins would still have the option of turning it off, but this would have to be explicitly configured.
I have a feeling that having strict uRPF as the default setting on an interface would be very badly received by a lot of ISP's. I know I certainly wouldn't like it very much.
Is it really the job of router vendors to protect the net from lazy/incompetent/ignorant network admins?
No, but I can't enable these features on all my router interfaces without causing delays/drops due to poor inital design quality and lack of long-term vision for linecards manufactured. The rush for time-to-market can cause you to lose in the long-term due to lack of features. - jared -- Jared Mauch | pgp key available via finger from jared@puck.nether.net clue++; | http://puck.nether.net/~jared/ My statements are only mine.