Apologies upfront for my not being able to successfully google this on my own... Is there an RFC or other standard that specifies that IPv4 connected devices must support the concepts of Subnet Mask and Default Gateway? I have a kludgy (<- technical term) vendor that has developed a custom AP that only has an IP address. Whilst cleaning up our network and turning off proxy-arp, lo and behold, it isn't really all that functional anymore. Thanks in advance, replies off-list welcome. - Scott
On Fri, 5 Aug 2005, Scott Altman wrote:
Apologies upfront for my not being able to successfully google this on my own...
Is there an RFC or other standard that specifies that IPv4 connected devices must support the concepts of Subnet Mask and Default Gateway?
I have a kludgy (<- technical term) vendor that has developed a custom AP that only has an IP address. Whilst cleaning up our network and turning off proxy-arp, lo and behold, it isn't really all that functional anymore.
like IP: http://www.faqs.org/rfcs/rfc791.html hth Steve
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.
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. I'd subject that thing's stack to some stress analysis - if they didn't get THAT, who knows what ELSE is evil/broken in the stack?
On Fri, Aug 05, 2005 at 03:09:53PM -0400, Valdis.Kletnieks@vt.edu 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?
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 -- Jay R. Ashworth jra@baylink.com Designer Baylink RFC 2100 Ashworth & Associates The Things I Think '87 e24 St Petersburg FL USA http://baylink.pitas.com +1 727 647 1274 "NPR has a lot in common with Nascar... we both turn to the left." - Peter Sagal, on Wait Wait, Don't Tell Me!
On Fri, 5 Aug 2005, Jay R. Ashworth wrote:
On Fri, Aug 05, 2005 at 03:09:53PM -0400, Valdis.Kletnieks@vt.edu 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
Thanks to all who replied, actually 791 doesn't specify that a host needs to implement these things; it lays out IP and how to use a network mask / gateway. RFC1122 (thanks to you off-listers) section 3.3.1.6 specifically (using the RFC's famed "MUST" verbiage) states that a host use a configurable subnet mask and default gateway. Oh believe me, if I had a choice, we would have not put this stuff in. It's here already and we're just trying to work around it. More specifically tell the vendor to get their act together and be a good network citizen. Thanks all! - Scott
participants (4)
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Jay R. Ashworth -
Scott Altman -
Stephen J. Wilcox -
Valdis.Kletnieks＠vt.edu