We have fwsms in cluster mode, when we configure a new acl and press enter the cpu goes high and comes down during day time (peak hrs). When we do the same during off peak hrs no problem. FWSM Firewall Version 2.3(2)5.
FWSM has fairly good amount of configuration. Otherwise the cpu usage is normal.
Also here is the excerpt from the FWSM configuration guide:
'Management access to the FWSM using Telnet, SSH, or HTTPS might cause a degradation in performance depending on the commands that you execute during the session. For example, if there are 50,000 current connections and you enter the show conn command, the CPU utilization is higher than if you do not enter the command. We recommend that you avoid executing commands on the FWSM
when high network performance is critical'
As it suggests, you should prefer configuring FWSM during off peak hours
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...