: At least 192MB (though 128MB may work for basic labs).

Router# reload

show flash

Several helpful resources and technical guides relate to using this specific image, particularly in network emulation environments like GNS3. Key Resources and Technical Articles

If you see "c2600-advipservicesk9-mz", you have crypto capabilities.

Support for stateful firewalls (Cisco IOS FW), Intrusion Prevention Systems (IPS), and IPsec VPNs for secure site-to-site communication.