Thank you Paul. I'm sorry, but I haven't found any information about it except that the maxium number of helper-address in an interface can be different depending on the router's model ... View more

Georg, I have activated CBAC in the router and when I do it the router writes automatically a configuration. But when it applies the new configuration, it shows an invalid input. This is a part of the console: ip inspect udp idle-time 1800      ^ % Invalid input detected at '^' marker. ip inspect name autosec_inspect cuseeme timeout 3600      ^ % Invalid input detected at '^' marker. ip inspect name autosec_inspect ftp timeout 3600      ^ % Invalid input detected at '^' marker. ip inspect name autosec_inspect http timeout 3600      ^ % Invalid input detected at '^' marker. ip inspect name autosec_inspect rcmd timeout 3600      ^ % Invalid input detected at '^' marker. ip inspect name autosec_inspect realaudio timeout 3600      ^ % Invalid input detected at '^' marker.       And when I try to do it manually then, this happens:   testing(config)#ip ins? % Unrecognized command testing(config)#ip ins ... View more

Georg, using the default IOS version CBAC is not available. I have tried to do what you had told me running the default IOS version: Router#auto secure                 --- AutoSecure Configuration --- *** AutoSecure configuration enhances the security of the router but it will not make router absolutely secure from all security attacks *** All the configuration done as part of AutoSecure will be shown here. For more details of why and how this configuration is useful, and any possible side effects, please refer to Cisco documentation of AutoSecure. At any prompt you may enter '?' for help. Use ctrl-c to abort this session at any prompt. If this device is being managed by a network management station, AutoSecure configuration may block network management traffic. Continue with AutoSecure? [no]: no Router#   Regards ... View more

Georg,   By default, the new routers run this IOS file: isr4300-universalk9.03.16.04b.S.155-3.S4b-ext.SPA.bin But I've downloaded one of the recommended IOS version for ISR 4331 in Cisco's web site: isr4300-universalk9.16.06.05.SPA.bin   Whatever, I've seen that there is not any IOS version for Cisco 4331 that is compatible with IP inspect: https://learningnetwork.cisco.com/thread/86420 https://community.cisco.com/t5/firewalls/firewall-on-isr-4300-router/td-p/2703291 ... View more