ejm@riscit.NOC.Vitalink.COM (Erik J. Murrey) (03/05/91)
I see in RFC950 and the like that the subnet portion of the IP address should not be zero, since it is reserved. This seems to stem from the concept of 0 meaning "this" network; presumably subnet "0" means "this" subnet. (i.e. if we have 128.1.0.0, with a 255.255.255.0 mask, then an address of 128.1.0.x is illegal) Is this still a real restriction on the address space? --- Erik J. Murrey Vitalink Communications NOC ejm@NOC.Vitalink.COM ...!uunet!NOC.Vitalink.COM!ejm
jonson@SERVER.AF.MIL (Lt. Matt Jonson) (03/06/91)
<Erik J. Murrey writes> > Subject: Subnet Number 0 > Message-Id: <1423@nocsun.NOC.Vitalink.COM> > > I see in RFC950 and the like that the subnet portion of the IP address > should not be zero, since it is reserved. This seems to stem from the > concept of 0 meaning "this" network; presumably subnet "0" means > "this" subnet. (i.e. if we have 128.1.0.0, with a 255.255.255.0 mask, > then an address of 128.1.0.x is illegal) > Absolutely. Take a look at RFC 1122, section 3.2.1.3. There are some caveats for using such addresses in IP address discovery routines. /matt -- Lt Matthew W Jonson jonson@server.af.mil snail-mail: Network Systems Engineer 205-279-4075 SSC/SSMT USAF DDN Program Office AV: 596-4075 Gunter AFB, AL 36114