Fire box locks up caz of one of these
1. Excessive use of proxies in the firebox. Proxies put more load on the firebox as compared to filters, excessive load *may* cause firebox lockups.
Resolution - There is no specific limit to the number of proxies but it is recommended to avoid their unnecessary use. For ex. it is always recommended to use an SMTP proxy to check the Incoming traffic and an SMTP filter for Outgoing. If Outgoing SMTP traffic from the network is high, proxying the same will put a lot of load on the firebox.
2. Any layer 2 devices like hubs or switches behind the firebox which are prone to network loops and might cause the firebox to lockup.
Resolution - This is one of the prominent reasons for lockups. The only way to check for the same is to bypass the switch and attach a single computer on the trusted interface of the firebox which would be possible only in off-hours.
3. Any Virus infected peers behind the firebox which could be generating excessive traffic and occupying memory.
Resolution - Can be identified by watching the traffic monitor or running a latest virus update on the network.
4. Proxy Memory allocation - To see what is FB memor
y utilization (global and per process) you can take look at the StatusReport tab in the Firebox System Manager.
Resolution - Can be identified through Status Report.
5. SYN Flood protection setting Enabled
Resolution - If you are using this option, disable it for the time being. SYN Flood protection setting is located in the Policy Manager -> Setup -> Intrusion Prevention -> Default Packet Handling.