[15351] in North American Network Operators' Group
Re: Smurfing
daemon@ATHENA.MIT.EDU (Craig A. Huegen)
Fri Feb 13 18:57:28 1998
Date: Fri, 13 Feb 1998 15:46:12 -0800 (PST)
From: "Craig A. Huegen" <chuegen@quadrunner.com>
To: Randy Bush <randy@psg.com>
cc: Havard.Eidnes@runit.sintef.no, nanog@merit.edu
In-Reply-To: <m0y3TyC-0007zYC@rip.psg.com>
On Fri, 13 Feb 1998, Randy Bush wrote:
==>> o All router administrators on the immediately reachable
==>> Internet needs to turn off directed broadcasts on their router
==>> interfaces. It's conceivable that "a significant portion of
==>> all" would do as well, but the magnitude of this problem
==>> boggles the mind. First of all, we'd need to distribute the
==>> appropriate amount of clue to all the corners of the net where
==>> this needs to happen. Maybe, just maybe, we'll get there
==>> sometime (I'm an optimist!).
==>
==>why should this not have become the default mode for all vendor
==>diustributed router code?
Because the routing RFC[1] states:
---
A router MAY have an option to disable receiving network-prefix-
directed broadcasts on an interface and MUST have an option to
disable forwarding network-prefix-directed broadcasts. These options
MUST default to permit receiving and forwarding network-prefix-
directed broadcasts.
---
"network-prefix-directed broadcasts" are the ones spoken of here.
A router *MUST* have an option to turn them off and *MUST* default to
forwarding them. The "MAY" stated here (to clarify) means that the router
MAY choose not to respond to another host pinging a broadcast address.
[1] RFC-1812, "Requirements for IP Version 4 Routers"; F. Baker; June
1995.
/cah
