Re: [SLUG] LAN config

From: Eben King (eben1@tampabay.rr.com)
Date: Wed May 31 2006 - 09:19:58 EDT

On Wed, 31 May 2006, Chris Mathey wrote:

> Eben King wrote:
>> On Wed, 31 May 2006, Kwan Lowe wrote:
>>
>>>> On Tue, 30 May 2006, Eben King wrote:
>>>>
>>>>> On Tue, 30 May 2006, Chris Mathey wrote:
>>>>>
>>>>>> Now everything will work perfectly :)
>>>>
>>>>
>>>> Yep, it works. Thanks. But, I can no longer contact the Netgear router
>>>> (#2) from anywhere. Is this an expected side effect, or have I done
>>>> something wrong?
>>>
>>>
>>> If you mean "contact" for management (i.e., the web page), you need to
>>> enable "Remote Management" from an address or address range.
>>
>>
>> Figured it out. I had given the router a netmask of 255.255.255.15 (last
>> two quads, in binary: 1111 1111.0000 1111). Windows insists that any
>> netmask has a contiguous string of 1s. So I couldn't match the netmask.
>> Oops. So I performed a hard reset, which made everything factory-fresh,
>> then fixed it. Who knows if it honored that bizarre netmask.
>>
>> Now I can contact either router (i.e.: go to their web page) from any
>> computer.
>
> That makes sense 255.255.255.15 is not a valid mask.

The conversation at
http://lists.netfilter.org/pipermail/netfilter/2001-October/027593.html says
discontiguous netmasks are accepted by Linux tools, and violate only an
IETF ruling.

> here are the valid masks:
>
>
> 255.255.255.255.0 11111111.11111111.11111111.00000000 254 hosts
> 255.255.255.255.128 11111111.11111111.11111111.10000000 126 hosts
> 255.255.255.255.192 11111111.11111111.11111111.11000000 62 hosts
> 255.255.255.255.224 11111111.11111111.11111111.11100000 30 hosts
> 255.255.255.255.240 11111111.11111111.11111111.11110000 14 hosts
> 255.255.255.255.248 11111111.11111111.11111111.11111000 6 hosts
> 255.255.255.255.252 11111111.11111111.11111111.11111100 2 hosts
> 255.255.255.255.254 11111111.11111111.11111111.11111110 0 hosts

Do the {low,high}est address actually _mean_ something special, or are they
just typically used that way? What about using x.x.x.x/32 to refer to one
host? Is that a pathological case and therefore requires a special case? 

-- 
-eben    QebWenE01R@vTerYizUonI.nOetP    royalty.no-ip.org:81

And we never failed to fail / It was the easiest thing to do -- CSN
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