Path: utzoo!attcan!uunet!zephyr.ens.tek.com!uw-beaver!milton!dali.cs.montana.edu!uakari.primate.wisc.edu!zaphod.mps.ohio-state.edu!sdd.hp.com!hplabs!hplred!haddad From: haddad@hplred.HP.COM (R. Peter Haddad) Newsgroups: comp.protocols.tcp-ip Subject: Re: subnets Message-ID: <11080002@hplred.HP.COM> Date: 23 Oct 90 18:09:16 GMT References: Organization: Hewlett Packard Labs, Palo Alto CA Lines: 33 / hplred:comp.protocols.tcp-ip / jacobson@cs.iastate.edu (Doug Jacobson) / 2:19 pm Oct 22, 1990 / I have two general questions about subnetting in TCP/IP. At Iowa State University we have a class B address and our campus network consists of a four large bridged Ethernet segments with a FDDI backbone used to connect these segments. Some of the segments contain IP Gateways. The campus was using transparent subnetting until about a month aao when the campus changed to unsubnetted. The Broadcast addresses and the Netmasks have been changed. (Broadcast changed from 129.186.X.255 to 129.186.255.255 and the netmask changed from 255.255.0.0 to 255.255.255.0). The questions I are: 1) Should we have changed the campus to not support transparent subnetting even though we do have some true subnets within our domain. 2) How do other organizations with class B addresses set up their networks and do they use transparent subnetting. You can mail your responses to me at doug@isuee1.ee.iastate.edu if there is enough interest I will post the results to question 2. ---------- Doug : Perhaps I am missing something here. Your broadcast address seems to have changed to accomodate a 0 length subnet field, therefore a 16 bit host field. Your netmask however has been changed to allow an 8 bit subnet field, and therefore an 8 bit host field. Am I misunderstanding the situation ? What do you mean by "transparent" subnetting ? Peter Haddad HPLabs Network Eng.