entering /32 subnet mask on ppp wan interface

Simon

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Mar 22, 2006, 4:19:15 PM3/22/06

to

Hi

Can I enter a /32 subnet mask on a ppp dialer0 interface. It is
negotiated at the moment but I want it to be hard-coded.

When entering the command on the dialer0 inteface I get the error
below:

router(config)#int dialer0
router(config-if)#ip address 111.222.111.222 255.255.255.255
Bad mask /32 for address 111.222.111.222
router(config-if)#

The router is an 837 with IOS v12.4.7

Is it possible to have a subnet mask for a ppp wan interface of either
0.0.0.0 or 255.255.255.255. It certainly negotiates it as I can see it
in the routing table.

thanks
si
--
Simon

Patrick M. Hausen

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Mar 22, 2006, 4:21:35 PM3/22/06

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Hi!

Simon <si.u...@gmail.com> wrote:

> Can I enter a /32 subnet mask on a ppp dialer0 interface. It is
> negotiated at the moment but I want it to be hard-coded.
>
> When entering the command on the dialer0 inteface I get the error
> below:
>
> router(config)#int dialer0
> router(config-if)#ip address 111.222.111.222 255.255.255.255
> Bad mask /32 for address 111.222.111.222
> router(config-if)#

I don't have a suitable router at hand to verify your problem,
but if I'm not entirely mistaken, you can definitely use:

interface Loopback0
ip address 1.2.3.4 255.255.255.255

interface Dialer0
ip unnumbered Loopback0

HTH,
Patrick
--
punkt.de GmbH Internet - Dienstleistungen - Beratung
Vorholzstr. 25 Tel. 0721 9109 -0 Fax: -100
76137 Karlsruhe http://punkt.de

Simon

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Mar 22, 2006, 4:39:54 PM3/22/06

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On 22 Mar 2006 22:21:35 +0100, "Patrick M. Hausen" <hau...@nospam.de>
wrote:

>Hi!
>
>Simon <si.u...@gmail.com> wrote:
>
>> Can I enter a /32 subnet mask on a ppp dialer0 interface. It is
>> negotiated at the moment but I want it to be hard-coded.
>>
>> When entering the command on the dialer0 inteface I get the error
>> below:
>>
>> router(config)#int dialer0
>> router(config-if)#ip address 111.222.111.222 255.255.255.255
>> Bad mask /32 for address 111.222.111.222
>> router(config-if)#
>
>I don't have a suitable router at hand to verify your problem,
>but if I'm not entirely mistaken, you can definitely use:
>
>interface Loopback0
> ip address 1.2.3.4 255.255.255.255
>
>interface Dialer0
> ip unnumbered Loopback0
>

Hi Patrick

That worked a treat, thanks.

regards
si

--
Simon

Merv

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Mar 22, 2006, 4:46:18 PM3/22/06

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/31 is the best you can do on the dialer interface itself

cat6#conf t
Enter configuration commands, one per line. End with CNTL/Z.
cat6(config)#int dialer 0
cat6(config-if)# ip address 111.222.111.222 255.255.255.255

Bad mask /32 for address 111.222.111.222

cat6(config-if)# ip address 111.222.111.222 255.255.255.254

anyb...@hotmail.com

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Mar 22, 2006, 5:32:31 PM3/22/06

to

> Can I enter a /32 subnet mask on a ppp dialer0 interface. It is
> negotiated at the moment but I want it to be hard-coded.

> When entering the command on the dialer0 inteface I get the error
> below:

> router(config)#int dialer0
> router(config-if)#ip address 111.222.111.222 255.255.255.255

> Bad mask /32 for address 111.222.111.222

> router(config-if)#

This has changed from 12.3 something.
Old software permitted /32 mask, new software didn't.

I found out the hard way.

Remote software upgrade resulted in lost
connectivity. Needed site visit to fix.

Doug McIntyre

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Mar 23, 2006, 12:47:59 AM3/23/06

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Sounds like you might want

int dialer0
ip address negotiated

??

If, even if you know which IP it will get, it can still negotiate it
in IPCP to get the same one each time.

Aaron Leonard

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Mar 23, 2006, 8:40:31 PM3/23/06

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On 23 Mar 2006 05:47:59 GMT, Doug McIntyre <mer...@geeks.org> wrote:

~ Simon <si.u...@gmail.com> writes:
~ >Can I enter a /32 subnet mask on a ppp dialer0 interface. It is
~ >negotiated at the moment but I want it to be hard-coded.
~
~ >When entering the command on the dialer0 inteface I get the error
~ >below:
~
~ >router(config)#int dialer0
~ >router(config-if)#ip address 111.222.111.222 255.255.255.255
~ >Bad mask /32 for address 111.222.111.222
~ >router(config-if)#
~
~ >The router is an 837 with IOS v12.4.7
~
~ >Is it possible to have a subnet mask for a ppp wan interface of either
~ >0.0.0.0 or 255.255.255.255. It certainly negotiates it as I can see it
~ >in the routing table.
~
~
~ Sounds like you might want
~
~ int dialer0
~ ip address negotiated
~
~ ??
~
~ If, even if you know which IP it will get, it can still negotiate it
~ in IPCP to get the same one each time.

Assuming that the OTHER guy knows which IP address you should have, and
that you TRUST the other guy.