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Re: RFC for Mask/Gateway

  • From: Stephen J. Wilcox
  • Date: Fri Aug 05 15:56:41 2005

On Fri, 5 Aug 2005, Jay R. Ashworth wrote:

> 
> On Fri, Aug 05, 2005 at 03:09:53PM -0400, [email protected] wrote:
> > On Fri, 05 Aug 2005 13:55:58 CDT, Scott Altman said:
> > > Is there an RFC or other standard that specifies that IPv4 connected
> > > devices must support the concepts of Subnet Mask and Default Gateway?
> > 
> > No, because there's plenty of applications (embedded systems, for example),
> > where you have no need or desire to be able to talk to things off-local-net.
> 
> Which doesn't really excuse you from subnet mask, I wouldn't think.
> 
> You clearly don't need a default gateway if you're not going to reply
> to off-net packets, but how would you idenfity broadcast packets if you
> didn't know the netmask?

all bits set in the dst mac is one way.. not sure how you send them tho if you 
dont know the dstIP to put into the packet

Steve

> > > I have a kludgy (<- technical term) vendor that has developed a custom
> > > AP that only has an IP address.
> > 
> > Be afraid. Be very afraid.  Any vendor in *this* year who makes gear that
> > is supposed to connect edge devices to the rest of the net but doesn't
> > get the ideas of subnet masks and default gateways should be feared.
> 
> Indeed, run far, far away.
> 
> And yes, Scott: RFC 791.  It's not just a good idea...
> 
> Cheers,
> -- jra
>