I have a cisco 837 adsl router. I performed a security scan of my network and the following vulbnerability has been found:
Your firewall policy seems to allow UDP packets with a specific source port (for example, port 53) to pass through while it blocks UDP packets to the same destination ports but with a random source port.
In the Result section, the service lists up to 16 such destination ports that can be reached by the UDP probes with a source port of 53.
Is there an access list entry I can make to stop this vulnerability?
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...