Katt is correct. 127.0.0.0/8 is indeed reserved for loopback. Any and all of the addresses in the class A network refer to the local host. As for network and broadcast addresses, don't forget that computers work on binary so your description is not technically correct. Any address where the host portion is all 1's is a broadcast address, and any address where the host portion is all 0's is the network address. What this means is that if the host portion of the address spans a byte boundary you can indeed have legal address that end in .0 or .255.
For example: 10.1.0.0/8 is a legal address (Network is 00001010, and host is 00000001.00000000.00000000) 10.1.0.255/8 is also a legal address (Network is 00001010, and host is 00000001.00000000.11111111) On many routers the subnet address can also not be all zeros, but I'm not that is actually specified in the RFC's. In Cisco routers you can allow the use of all zero subnets with the "ip subnet zero" command. This can actually conserve quite a few addresses if you subnet in large chunks. Ben Setnick -----Original Message----- From: Robert Clark [mailto:[EMAIL PROTECTED]] Sent: Thursday, November 01, 2001 8:47 AM To: 'KaTT KaTT'; [EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL PROTECTED] Subject: RE: help - can someone explain this to me? KaTT KaTT wrote: > > 127.0.0.0 is a little bit different than the above. This was > basically a > blunder from the old school. 127.0.0.0 was used by the Unix > operating system > as the loopback network, and has been reserved. They took an > entire "class" I believe you meant 127.0.0.1, that's the default loopback address. Pinging 127.0.0.0 will result in an unspecified destination statement. Any IPs ending in .0 or .255 are broadcast addresses for the network.
