Messages in this thread | | | Date | Fri, 28 Jan 2000 15:43:40 -0800 (PST) | From | David Lang <> | Subject | Re: all zeroes/all ones used in host IP's... |
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some equipment (including Cisco routers if they have older firmware) do not allow network addresses with 0's in them. with the newer firmware there is a command you need to include in the configuration to allow it to use them.
Linux allows them without any problems.
David Lang
On Fri, 28 Jan 2000, Meelis Roos wrote:
> Date: Fri, 28 Jan 2000 22:01:25 +0200 > From: Meelis Roos <mroos@linux.ee> > To: linux-kernel@vger.rutgers.edu > Subject: Re: all zeroes/all ones used in host IP's... > > MAH> using "0's" in IP addresses. Nobody could categorically say > MAH> wether or not they are allowed or not including myself, so I > MAH> hunted down RFC 1123, and found the relevant section. > > It's really 1122 :) > > MAH> IP addresses are not permitted to have the value 0 or -1 for > MAH> any of the <Host-number>, <Network-number>, or <Subnet- > MHA> number> fields (except in the special cases listed above). > MAH> This implies that each of these fields will be at least two > MAH> bits long. > > MAH> I interpret the above as meaning that it is not legal to have a > MAH> network like this: > > MAH> 192.168.0.0/24 or 23.0.0.0/24 > > MAH> with hosts 192.168.0.1 through 192.168.0.254 or with hosts > MAH> 23.0.0.1 through 23.0.0.254. > > Why? 192.168.0.0 is a C class address, so it has the network number > 192.168.0 which is not 0. As 23.0 is not equal to 0. So they are > allowed. > > -- > Meelis Roos (mroos@tartu.cyber.ee) > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.rutgers.edu > Please read the FAQ at http://www.tux.org/lkml/ >
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