Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss

[Q] Why illegal IP: 192.168.40.1/255.255.255.224 ?

21 views
Skip to first unread message

Alex Bligh

unread,
Mar 19, 1996, 3:00:00 AM3/19/96
to fra...@pinewood.nl
fra...@pinewood.nl (Frank ten Wolde) wrote:
>Hello,
>
>Why does cisco not accept the following parameters for one
>of the network interface ports:
>
> IP address = 192.168.40.1
> Subnetmask = 255.255.255.224 (FF.FF.FF.E0)
>
>It *does* accept 192.168.40.33 ?

try adding to your config

ip subnet-zero
ip classless

Alex Bligh
Xara Networks

Tony Li

unread,
Mar 19, 1996, 3:00:00 AM3/19/96
to

Why does cisco not accept the following parameters for one
of the network interface ports:

IP address = 192.168.40.1
Subnetmask = 255.255.255.224 (FF.FF.FF.E0)

It *does* accept 192.168.40.33 ?

That's subnet zero... To enable it, configure "ip subnet-zero"

Tony

Frank ten Wolde

unread,
Mar 19, 1996, 3:00:00 AM3/19/96
to
Hello,

Why does cisco not accept the following parameters for one
of the network interface ports:

IP address = 192.168.40.1
Subnetmask = 255.255.255.224 (FF.FF.FF.E0)

It *does* accept 192.168.40.33 ?

Any help appreciated. Please mail to: fra...@pinewood.nl

Thankx,

-Frank
--
----------------------------------------------------------------------
F.W. ten Wolde (PA3FMT) Pinewood Automation B.V.
E-mail: fra...@pinewood.nl Kluyverweg 2a
Phone: +31-15 2682543 2629 HT Delft

Paul Ferguson

unread,
Mar 19, 1996, 3:00:00 AM3/19/96
to
At 02:00 PM 3/19/96 GMT, Frank ten Wolde wrote:

>Hello,
>
>Why does cisco not accept the following parameters for one
>of the network interface ports:
>
> IP address = 192.168.40.1
> Subnetmask = 255.255.255.224 (FF.FF.FF.E0)
>
>It *does* accept 192.168.40.33 ?
>
>Any help appreciated. Please mail to: fra...@pinewood.nl
>


The host address you are attempting to use resides in IP subnet 0.
Use the global command 'ip subnet-zero' to allow usage of host
addresses which reside in this subnet.

Subnetting with a subnet address of zero generally is not allowed
because of the confusion inherent in having a network and a subnet
with indistinguishable addresses. For example, if network 131.108.0.0
is subnetted as 255.255.255.0, subnet zero would be written as
131.108.0.0 -- which is identical to the network address.

See also:

http://www.cisco.com/warp/public/701/3.html

- paul

>Thankx,
>
>-Frank
>--
>----------------------------------------------------------------------
>F.W. ten Wolde (PA3FMT) Pinewood Automation B.V.
>E-mail: fra...@pinewood.nl Kluyverweg 2a
>Phone: +31-15 2682543 2629 HT Delft
>

--
Paul Ferguson || ||
Consulting Engineering || ||
Reston, Virginia USA |||| ||||
tel: +1.703.716.9538 ..:||||||:..:||||||:..
e-mail: pfer...@cisco.com c i s c o S y s t e m s


Bob Albrightson

unread,
Mar 20, 1996, 3:00:00 AM3/20/96
to
In article <franky.827244052@pwood1> fra...@pinewood.nl (Frank ten Wolde) writes:

Why does cisco not accept the following parameters for one
of the network interface ports:

IP address = 192.168.40.1
Subnetmask = 255.255.255.224 (FF.FF.FF.E0)

It *does* accept 192.168.40.33 ?

Because 192.168.40.1/27 is subnet zero. If you *must* use subnet zero
(not a good idea in all cases) then enable subnet zero processing:

ip subnet-zero

-bob


Andreas Fink

unread,
Mar 22, 1996, 3:00:00 AM3/22/96
to
In article <franky.827244052@pwood1>, fra...@pinewood.nl (Frank ten Wolde)
wrote:

> Hello,
>

> Why does cisco not accept the following parameters for one
> of the network interface ports:
>
> IP address = 192.168.40.1
> Subnetmask = 255.255.255.224 (FF.FF.FF.E0)
>
> It *does* accept 192.168.40.33 ?
>

> Any help appreciated. Please mail to: fra...@pinewood.nl

try

ip subnet-zero

and it will work

0 new messages