Explanation - This message appears when the security appliance does not have a UDP server that services the UDP request. The message can also indicate a TCP packet that does not belong to any session on the security appliance. In addition, this message appears (with the service snmp) when the security appliance receives an SNMP request with an empty payload, even if it is from an authorized host. When the service is snmp, this message occurs a maximum of 1 time every 10 seconds so that the log receiver is not overwhelmed.
Recommended Action - In networks that heavily utilize broadcasting services such as DHCP, RIP or NetBios, the frequency of this message can be high. If this message appears in excessive number, it may indicate an attack.
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...