Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!ucsd!ucbvax!europa.interlan.COM!kasten
From: kasten@europa.interlan.COM (Frank Kastenholz)
Newsgroups: comp.protocols.tcp-ip
Subject: Re:  IP Addresses (Subnets)
Message-ID: <9006131741.AA09350@europa.Com>
Date: 13 Jun 90 17:41:45 GMT
Sender: usenet@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 39


 > From tcp-ip-RELAY@NIC.DDN.MIL Wed Jun 13 13:08:44 1990
 > From: sdd.hp.com!uakari.primate.wisc.edu!ark1!volleydog!rhott@ucsd.edu  (The VolleyDog)
 > Organization: Naval Surface Warfare Center, Dahlgren VA
 > Subject: IP Addresses (Subnets)
 > Sender: tcp-ip-relay@nic.ddn.mil
 > To: tcp-ip@nic.ddn.mil
 > 
 > I have a quick question, hopefully you will not flame to loudly with
 > regard to  viewing RFCs.  I looked through RFC 950 to try to determine
 > how to specify a host when using a subnet.  In my particular instance we
 > have a class B network.  I am interested in how one would specify
 > addresses when a subnet of 6 bits is used.
 > 
 > Suppose I want the 300th host on the 1 subnet of a class B network with
 > a netmask of 255.255.252!  Should I specify the IP address as
 > 128.38.1.300 or 128.38.253.44
 > 
 > I guess my overall question is:  Should I specify the addressing using
 > the 3rd octet field in the dot notation as the subnet or as the 3rd
 > octet of the 32 bit field? 
Bob:

From RFC 1117 (Internet Numbers):
	
   One commonly used notation for internet host addresses divides the
   32-bit address into four 8-bit fields and specifies the value of each
   field as a decimal number with the fields separated by periods.  This
   is called the "dotted decimal" notation.  For example, the internet
   address of VENERA.ISI.EDU in dotted decimal is 010.001.000.052, or
   10.1.0.52.

So, the correct number is 128.38.253.44.

This is not an "official standard" but it is common usage to the degree that
no one does anything different.

Frank Kastenholz
Racal Interlan