發信人：James Egan 日期：Fri, 14 Feb 1997 12:06:00 -0500 標題：Re: IP Address Subnetting/Distribution.... 信群：comp.os.ms-windows.nt.admin.misc,comp.unix.solaris,tw.bbs.comp.mswindows.nt,tw. 看板： 代號：<33049B78.4576@iai.com> 組織：Integrated Architectures, Inc. Jimmy K. Lai wrote: > > Greetings... > > senario 1: > > A company "A" has a class C ip address, just about enough for 200 employee > each having their own ip address and network devices. Currently, these 200 > emplyees are on a single LAN (no subnet) and it worked fine with just email > traffic. One sunny day, 25 of these emplyees decided to move to another > office location (local office) and starting a CAD/image designing group > (which shares large image files). With just a single class C ip address at > hand, would dividing the C class be a wise solution? These 25 people are > connected through a WAN connection to the rest of 175 people (main office). > The rest of 175 people can work great without create any subnet between > them... actually this is preferred. > > 1. Is dividing this class C address into subnets a wise solution (for > reducing the WAN traffic, since these 25 people mainly shares the large > image files within their own group)? > > 2. If so, how many? (If you divide into about ~25 ip addresses per subnet, > it would require about ~8 unnessary briding equipments for the rest of 175 > employees. If you divide just into two subnets -- one local office, one > main office -- it would be waste of ip addresses on the local office and > deficient ips for the main office). > > 3. Any better solution other than dividing into subnets? Is there anyway > to create unequal sized subnets.. like one subnet 25 ips and the other 175 > ips? Everyone in this company preferred a static ip environment (i.e. > DHCP is not being considered now for various reasons). > > Thank you for your help. By the way, this is a true situation we > encountered previously. > > -- > > Jimmy K. Lai > Lucent Technologies Jimmy: You will probably have trouble if you try to use a variable subnet mask. Therefore you will only be able to subnet as 128/128 unless you make 4 or 8 subnets, in which case you will lose some of your addresses. Specifically the all-0s and all-1s address in each subnet. Although it's a lot of work for you, consider using an RFC1918 address for your network or subnet. Good luck. /Jim/ -- James P. Egan | Integrated Architectures, Inc. Jim.Egan@iai.com | "Trust no one" .