SDM connection lost when applying firewall rules

[acid_sysadmin]

After adding new firewall rules on a Cisco 1801 and hitting 'Apply settings', the progress window will scroll for a short period before a dialog is displayed that reads:

"Connection lost.

SDM lost the connection to your router because of a communication error. SDM will shut down when you click the OK button.

Re-launch SDM to continue working. Enter the same URL you used to re-start SDM."

Upon re-starting SDM, the rules have not been applied. The behaviour is consistent. I am using SDM 2.5 and have tried SDM 2.4.x and multiple versions of the Java VM.

Any ideas why I am unable to apply the firewall settings?

Your help would be most appreciated.

C.

[smahbub]

The router that you are configuring must be using a Cisco IOS image that supports the Firewall feature set in order for you to be able to use Cisco Router and Security Device Manager (Cisco SDM) to configure a firewall on the router.

Refer the following url for more info on settinf firewall using SDM:

http://www.cisco.com/en/US/docs/routers/access/cisco_router_and_security_device_manager/25/software/user/guide/Fwall.html

[acid_sysadmin]

Thanks smahbub,

In the past I have been able to apply the firewall settings without incident.

I think it might be relevant that when I click 'apply settings' the count of commands increases by approximately 100 every time. It started to error after the number of commands exceeded around 2500.

I thought that the included 32MB CF card might be too small so I upgraded to a 512MB but that didn't seem to make any difference.

C.