nanog mailing list archives
Re: Question about subnetting /24's
From: I Am Not An Isp <patrick () ianai net>
Date: Thu, 18 Mar 1999 20:06:48 -0800
At 08:42 PM 3/18/99 -0500, Scott Gifford wrote:
I have a /24 network I want to subnet into two /25's. For realism's sake, let's call the network 216.40.155.0/24 (mask 255.255.255.0) So I have two 126-host networks, namely 216.40.155.0/25 (mask 255.255.255.128) 216.40.155.128/25 (mask 255.255.255.128) The person with whom I was calmly discussing the matter said that this configuration didn't make any sense, because my first subnet had all zeroes in the last octet, so it was an all-zeroes subnet; and the second had all ones on the last octet, so it was an all-ones subnet. And that these subnets were reserved as the network subnet, and the broadcast subnet, much as all-zeroes and all-ones in the host portion indicate the network and broadcast addresses.
He is correct for "classful" networking. If you run classless IP, his comments are irrelevant.
Both myself and the customer are using Bay Networks routers.
Ahhhhhh. I see your problem. :p
If anybody else is interested in this, let me know, and I'll summarize direct responses to the list.
I'm afraid that most people here know better. But thanx anyway.
------Scott.
TTFN, patrick I Am Not An Isp - www.ianai.net ISPF, The Forum for ISPs by ISPs, <http://www.ispf.com> "Think of it as evolution in action." - Niven & Pournelle
Current thread:
- Question about subnetting /24's Scott Gifford (Mar 18)
- Re: Question about subnetting /24's Michael Dillon (Mar 18)
- Re: Question about subnetting /24's Randy Bush (Mar 19)
- Re: Question about subnetting /24's I Am Not An Isp (Mar 18)
- Re: Question about subnetting /24's Chris MacFarlane (Mar 19)
- <Possible follow-ups>
- Re: Question about subnetting /24's Michael Dillon (Mar 18)
- Re: Question about subnetting /24's I Am Not An Isp (Mar 18)
- Re: Question about subnetting /24's Brett_Watson (Mar 18)
- Re: Question about subnetting /24's bmanning (Mar 18)
- Re: Question about subnetting /24's Michael Dillon (Mar 18)