Where's the netmask stored on ASA

Unanswered Question
May 27th, 2008

Hi all,

I have a question about the network objects on an ASA running V 8.0(3). After creating an network object with the corresponding netmask in ASDM I cant see it via CLI. Thers just the name without netmask. Where is the netmask stored? How does the ASA deal with this objects and netmasks?

Kind regards and thanks in advance


I have this problem too.
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Farrukh Haroon Fri, 05/30/2008 - 05:44

Perhaps its not showing because you are using the default network mask, for example for Class-C addresses you are using /24. like

Or another possibility is that you are using a /32 mask, which the firewall is replacing with the 'host' keyword?



blaesingmarco Fri, 06/06/2008 - 00:29

Hello Happs.

I think you are right. The Asa knows which mask fits to the IP.

But for example the IP can be configured with /32 /30 /29 /28 mask as a network object in asdm.

But the mask is not shown in the config via cli.



Farrukh Haroon Fri, 06/06/2008 - 02:43

If you configure the address as /8, it should not show as it is a Class A address and this is the default mask for it. /32 mask should show as 'host'. But all others should show in the CLI, otherwise how will the ASA differentiate between /28 and /30.

Also please remember ASA uses subnet mask and not wild-card mask.

Can you show the output of:

show run all object-group?


show run object-group



blaesingmarco Fri, 06/06/2008 - 03:40

Thanks for your reply.

When I configure in the ASDM the network object testnet

it is shown in CLI name testnet

No mask anywhere in the config.After creating an network object group and put the network object in this group the netmask is shown in the CLI. But where is it stored before?



Farrukh Haroon Fri, 06/06/2008 - 03:57

Oh I get it now, you are confusing the 'object-group' command with the 'name' command.

The 'name' command does not support any netmask whatsoever, it is just like how u do 'ip host' on the router. However personally I hate to use them, firstly its difficult to troubleshoot and view logs, people are usually doing 'show log | inc' and they get nothing :), because they are supposed to do 'show log | include ISA-SERVER'. Similarly to date Cisco MARS also does not support it.

The netmask you configure (in ASDM) will be visible by:

show run object-group

and NOT by

show run name

You just CALL that name in the object-group command (if you don't want in to to type the IP address and make configs more readable).

Have a look at the following:






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